diff --git a/src/main/scala/fr/ynerant/leveleditor/api/editor/Case.scala b/src/main/scala/fr/ynerant/leveleditor/api/editor/Case.scala
index 79bbd9f..f084bd7 100644
--- a/src/main/scala/fr/ynerant/leveleditor/api/editor/Case.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/api/editor/Case.scala
@@ -1,11 +1,10 @@
 package fr.ynerant.leveleditor.api.editor
 
-import fr.ynerant.leveleditor.api.editor.Collision.Collision
 import fr.ynerant.leveleditor.api.editor.sprites.Sprite
 
 
 object Case {
-	def create(posX: Int, posY: Int, couche1: Sprite, couche2: Sprite, couche3: Sprite, collision: Collision): Case = {
+	def create(posX: Int, posY: Int, couche1: Sprite, couche2: Sprite, couche3: Sprite, collision: String): Case = {
 		val c = new Case
 		c.x = posX
 		c.y = posY
@@ -23,7 +22,7 @@ class Case {
 	private var couche1 = null: Sprite
 	private var couche2 = null: Sprite
 	private var couche3 = null: Sprite
-	private var collision = null: Collision
+	private var collision = null: String
 
 	def getPosX: Int = x
 
@@ -35,7 +34,7 @@ class Case {
 
 	def getCoucheThree: Sprite = couche3
 
-	def getCollision: Collision = collision
+	def getCollision: String = collision
 
 	override def toString: String = "{Case x=" + x + " y=" + y + " couche1=" + couche1 + " couche2=" + couche2 + " couche3=" + couche3 + " collision=" + collision.toString.toUpperCase + "}\n"
 }
diff --git a/src/main/scala/fr/ynerant/leveleditor/api/editor/Collision.scala b/src/main/scala/fr/ynerant/leveleditor/api/editor/Collision.scala
index cacf513..5de47e7 100644
--- a/src/main/scala/fr/ynerant/leveleditor/api/editor/Collision.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/api/editor/Collision.scala
@@ -1,6 +1,9 @@
 package fr.ynerant.leveleditor.api.editor
 
-object Collision extends Enumeration {
-	type Collision = Value
-	val FULL, PARTIAL, ANY = Value
+object Collision {
+	val FULL: String = "FULL"
+	val PARTIAL: String = "PARTIAL"
+	val ANY: String = "ANY"
+
+	val values: IndexedSeq[String] = IndexedSeq(FULL, PARTIAL, ANY)
 }
diff --git a/src/main/scala/fr/ynerant/leveleditor/api/editor/EditorAPI.scala b/src/main/scala/fr/ynerant/leveleditor/api/editor/EditorAPI.scala
index baa02e4..9f12661 100644
--- a/src/main/scala/fr/ynerant/leveleditor/api/editor/EditorAPI.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/api/editor/EditorAPI.scala
@@ -3,22 +3,19 @@ package fr.ynerant.leveleditor.api.editor
 import java.awt.Color
 import java.awt.image.BufferedImage
 import java.io._
-import java.lang.reflect.Type
 import java.nio.charset.StandardCharsets
-import java.util
 import java.util.zip.{GZIPInputStream, GZIPOutputStream}
 
-import com.google.gson.{Gson, GsonBuilder, JsonDeserializationContext, JsonDeserializer, JsonElement, JsonPrimitive, JsonSerializationContext, JsonSerializer}
-import fr.ynerant.leveleditor.api.editor.Collision.Collision
-import fr.ynerant.leveleditor.editor.Map
+import fr.ynerant.leveleditor.editor.GMap
 import javax.swing.JFileChooser
 import javax.swing.filechooser.FileNameExtensionFilter
+import net.liftweb.json._
 
 object EditorAPI {
 	private var LAST_FILE = null: File
 
 	def toRawMap(width: Int, height: Int): RawMap = {
-		val cases = new util.ArrayList[RawCase]
+		var cases = Nil: List[RawCase]
 		var y = 1
 		while ( {
 			y < height
@@ -28,7 +25,7 @@ object EditorAPI {
 				x < width
 			}) {
 				val c = RawCase.create(x / 16, y / 16, RawSprite.BLANK, RawSprite.BLANK, RawSprite.BLANK, Collision.ANY)
-				cases.add(c)
+				cases ::= c
 
 				x += 16
 			}
@@ -38,20 +35,6 @@ object EditorAPI {
 		RawMap.create(cases, width, height)
 	}
 
-	def createGson: Gson = {
-		val builder = new GsonBuilder
-		builder.registerTypeAdapter(classOf[Collision.Collision], new JsonDeserializer[Collision.Collision] {
-			override def deserialize(jsonElement: JsonElement, `type`: Type, jsonDeserializationContext: JsonDeserializationContext): Collision = Collision.withName(jsonElement.getAsString)
-		})
-		builder.registerTypeAdapter(classOf[Collision.Collision], new JsonSerializer[Collision.Collision] {
-			override def serialize(t: Collision, `type`: Type, jsonSerializationContext: JsonSerializationContext): JsonElement = new JsonPrimitive(t.toString)
-		})
-		builder.enableComplexMapKeySerialization
-		builder.serializeNulls
-		builder.setPrettyPrinting()
-		builder.create
-	}
-
 	def createJFC: JFileChooser = {
 		val jfc = new JFileChooser
 		jfc.setFileFilter(new FileNameExtensionFilter("Fichiers monde (*.gmap, *.dat)", "gmap", "dat"))
@@ -80,7 +63,8 @@ object EditorAPI {
 	}
 
 	def save(file: File, map: RawMap): Unit = {
-		val json = createGson.toJson(map)
+		implicit val formats: DefaultFormats.type = DefaultFormats
+		val json = Serialization.writePretty(map)
 		try {
 			assert(file.createNewFile)
 			val bos = new BufferedOutputStream(new GZIPOutputStream(new FileOutputStream(file)))
@@ -92,7 +76,7 @@ object EditorAPI {
 		}
 	}
 
-	def open: Map = {
+	def open: GMap = {
 		val jfc = createJFC
 		var file = null: File
 		jfc.showOpenDialog(null)
@@ -119,12 +103,13 @@ object EditorAPI {
 			case e: IOException =>
 				e.printStackTrace()
 		}
-		createGson.fromJson(json, classOf[RawMap])
+		implicit val formats: DefaultFormats.type = DefaultFormats
+		parse(json).extract[RawMap]
 	}
 
-	def open(f: File): Map = open(getRawMap(f))
+	def open(f: File): GMap = open(getRawMap(f))
 
-	def open(map: RawMap): Map = {
+	def open(map: RawMap): GMap = {
 		if (map.getFont == null) {
 			val baseWidth = map.getWidth
 			val baseHeight = map.getHeight
@@ -155,6 +140,6 @@ object EditorAPI {
 			}
 			map.setFont(image)
 		}
-		new Map(map)
+		new GMap(map)
 	}
 }
diff --git a/src/main/scala/fr/ynerant/leveleditor/api/editor/RawCase.scala b/src/main/scala/fr/ynerant/leveleditor/api/editor/RawCase.scala
index 79706b5..548fce6 100644
--- a/src/main/scala/fr/ynerant/leveleditor/api/editor/RawCase.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/api/editor/RawCase.scala
@@ -1,9 +1,7 @@
 package fr.ynerant.leveleditor.api.editor
 
-import fr.ynerant.leveleditor.api.editor.Collision.Collision
-
 object RawCase {
-	def create(posX: Int, posY: Int, couche1: RawSprite, couche2: RawSprite, couche3: RawSprite, collision: Collision): RawCase = {
+	def create(posX: Int, posY: Int, couche1: RawSprite, couche2: RawSprite, couche3: RawSprite, collision: String): RawCase = {
 		new RawCase(posX, posY, couche1, couche2, couche3, collision)
 	}
 
@@ -12,7 +10,7 @@ object RawCase {
 	}
 }
 
-case class RawCase(var x: Int, var y: Int, var couche1: RawSprite, var couche2: RawSprite, var couche3: RawSprite, var collision: Collision) {
+case class RawCase(var x: Int, var y: Int, var couche1: RawSprite, var couche2: RawSprite, var couche3: RawSprite, var collision: String) {
 	def getPosX: Int = x
 
 	def getPosY: Int = y
@@ -23,9 +21,9 @@ case class RawCase(var x: Int, var y: Int, var couche1: RawSprite, var couche2:
 
 	def getCoucheThree: RawSprite = couche3
 
-	def getCollision: Collision = collision
+	def getCollision: String = collision
 
-	def setCollision(collision: Collision): Unit = {
+	def setCollision(collision: String): Unit = {
 		this.collision = collision
 	}
 }
diff --git a/src/main/scala/fr/ynerant/leveleditor/api/editor/RawMap.scala b/src/main/scala/fr/ynerant/leveleditor/api/editor/RawMap.scala
index 2ebead2..6264c28 100644
--- a/src/main/scala/fr/ynerant/leveleditor/api/editor/RawMap.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/api/editor/RawMap.scala
@@ -1,50 +1,45 @@
 package fr.ynerant.leveleditor.api.editor
 
-import fr.ynerant.leveleditor.editor.Map
 import java.awt.image.BufferedImage
-import java.util
-import java.util.stream.Collectors
 
-import com.google.gson.Gson
+import fr.ynerant.leveleditor.editor.GMap
+import net.liftweb.json._
 
 
 object RawMap {
-	def create(cases: util.List[RawCase], width: Int, height: Int): RawMap = {
+	def create(cases: List[RawCase], width: Int, height: Int): RawMap = {
 		new RawMap(cases, width, height)
 	}
 
-	def create(map: Map): RawMap = {
-		val raw = new RawMap(new util.ArrayList[RawCase], 0, 0)
-		raw.width = map.getWidth
-		raw.height = map.getHeight
-		raw.cases = new util.ArrayList[RawCase]
-		map.getAllCases.forEach(c => raw.cases.add(RawCase.create(c)))
+	def create(map: GMap): RawMap = {
+		val raw = new RawMap(Nil, map.getWidth, map.getHeight)
+		map.getAllCases.foreach(c => raw.cases ::= RawCase.create(c))
 		raw
 	}
 }
 
-case class RawMap(var cases: util.List[RawCase], var width: Int, var height: Int) {
-	private var cases_map = null: util.HashMap[Integer, RawCase]
+case class RawMap(var cases: List[RawCase], var width: Int, var height: Int) {
+	private var cases_map = null: Map[Integer, RawCase]
 	private var font = null: BufferedImage
 
-	def getCases: util.List[RawCase] = cases
+	def getNeighbours(c: RawCase): Iterable[RawCase] = {
+		var list = Nil: List[RawCase]
+		list ::= getCase(c.getPosX, c.getPosY + 1)
+		list ::= getCase(c.getPosX + 1, c.getPosY)
+		list ::= getCase(c.getPosX, c.getPosY - 1)
+		list ::= getCase(c.getPosX - 1, c.getPosY)
+		list.filter((_c: RawCase) => _c != null && _c.getCollision.equals(Collision.ANY))
+	}
 
 	def getCase(x: Int, y: Int): RawCase = {
 		if (cases_map == null) {
-			cases_map = new util.HashMap[Integer, RawCase]
-			getCases.forEach(c => cases_map.put(c.getPosY * width + c.getPosX, c))
+			cases_map = Map()
+			getCases.foreach(c => cases_map = cases_map.updated(c.getPosY * width + c.getPosX, c))
 		}
-		cases_map.get(y * getWidth + x)
+		cases_map.getOrElse(y * getWidth + x, null)
 	}
 
-	def getNeighbours(c: RawCase): util.Collection[RawCase] = {
-		val list = new util.ArrayList[RawCase]
-		list.add(getCase(c.getPosX - 1, c.getPosY))
-		list.add(getCase(c.getPosX, c.getPosY - 1))
-		list.add(getCase(c.getPosX + 1, c.getPosY))
-		list.add(getCase(c.getPosX, c.getPosY + 1))
-		list.stream.filter((_c: RawCase) => _c != null && (_c.getCollision == Collision.ANY)).collect(Collectors.toList())
-	}
+	def getCases: List[RawCase] = cases
 
 	def getWidth: Int = width
 
@@ -56,5 +51,8 @@ case class RawMap(var cases: util.List[RawCase], var width: Int, var height: Int
 		this.font = font
 	}
 
-	override def toString: String = new Gson().toJson(this)
+	override def toString: String = {
+		implicit val formats: DefaultFormats.type = DefaultFormats
+		Serialization.writePretty(this)
+	}
 }
diff --git a/src/main/scala/fr/ynerant/leveleditor/api/editor/sprites/Category.scala b/src/main/scala/fr/ynerant/leveleditor/api/editor/sprites/Category.scala
index c691993..8b32892 100644
--- a/src/main/scala/fr/ynerant/leveleditor/api/editor/sprites/Category.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/api/editor/sprites/Category.scala
@@ -1,9 +1,9 @@
 package fr.ynerant.leveleditor.api.editor.sprites
 
-import java.util
+import scala.collection.mutable.ListBuffer
 
 object Category {
-	def create(name: String, sprites: util.List[Sprite]): Category = {
+	def create(name: String, sprites: ListBuffer[Sprite]): Category = {
 		val c = new Category
 		c.name = name
 		c.sprites = sprites
@@ -12,12 +12,16 @@ object Category {
 }
 
 class Category private() {
-	private var sprites = null: util.List[Sprite]
+	private var sprites = null: ListBuffer[Sprite]
 	private var name = null: String
 
 	def getName: String = name
 
-	def getSprites: util.List[Sprite] = sprites
+	def getSprites: ListBuffer[Sprite] = sprites
+
+	def addSprite(s: Sprite): Unit = {
+		this.sprites += s
+	}
 
 	override def toString: String = name
 }
diff --git a/src/main/scala/fr/ynerant/leveleditor/api/editor/sprites/Sprite.scala b/src/main/scala/fr/ynerant/leveleditor/api/editor/sprites/Sprite.scala
index 8909732..07ad085 100644
--- a/src/main/scala/fr/ynerant/leveleditor/api/editor/sprites/Sprite.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/api/editor/sprites/Sprite.scala
@@ -2,15 +2,13 @@ package fr.ynerant.leveleditor.api.editor.sprites
 
 import java.awt._
 import java.awt.image.BufferedImage
-import java.util
-import java.util.ArrayList
 
+import scala.collection.mutable.ListBuffer
 
 object Sprite {
-	val BLANK = new Sprite(new BufferedImage(16, 16, BufferedImage.TYPE_INT_ARGB), Category.create("blank", new util.ArrayList[Sprite]), 0)
+	val BLANK = new Sprite(new BufferedImage(16, 16, BufferedImage.TYPE_INT_ARGB), Category.create("blank", ListBuffer()), 0)
 
-	val g: Graphics2D
-	= BLANK.getImage.createGraphics
+	val g: Graphics2D = BLANK.getImage.createGraphics
 	g.setComposite(AlphaComposite.Clear)
 	g.setColor(new Color(0, true))
 	g.fillRect(0, 0, 16, 16)
@@ -18,7 +16,7 @@ object Sprite {
 }
 
 class Sprite(val img: BufferedImage, val cat: Category, val index: Int) {
-	if (!this.cat.getSprites.contains(this)) this.cat.getSprites.add(this)
+	if (!this.cat.getSprites.contains(this)) this.cat.addSprite(this)
 
 	def getImage: BufferedImage = this.img
 
diff --git a/src/main/scala/fr/ynerant/leveleditor/api/editor/sprites/SpriteRegister.scala b/src/main/scala/fr/ynerant/leveleditor/api/editor/sprites/SpriteRegister.scala
index 2c1559d..34f83d2 100644
--- a/src/main/scala/fr/ynerant/leveleditor/api/editor/sprites/SpriteRegister.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/api/editor/sprites/SpriteRegister.scala
@@ -1,19 +1,20 @@
 package fr.ynerant.leveleditor.api.editor.sprites
 
-import java.io.{BufferedInputStream, BufferedReader, File, FileInputStream, IOException, InputStreamReader}
+import java.io.{BufferedInputStream, File, FileInputStream, IOException}
 import java.net.{URISyntaxException, URLDecoder}
 import java.nio.file.{Files, Paths}
-import java.util
 import java.util.Objects
 import java.util.jar.JarFile
 
-import com.google.gson.Gson
-import javax.imageio.ImageIO
 import fr.ynerant.leveleditor.client.main.Main
+import javax.imageio.ImageIO
+import net.liftweb.json._
+
+import scala.collection.mutable.ListBuffer
 
 object SpriteRegister {
-	private var nameToCoords = null: util.Map[String, util.List[util.List[Double]]]
-	private val sprites = new util.HashMap[String, Category]
+	private var nameToCoords = Map(): Map[String, List[List[Int]]]
+	private var sprites = Map(): Map[String, Category]
 
 	@throws[IOException]
 	def unpack(): Unit = {
@@ -63,32 +64,32 @@ object SpriteRegister {
 	}
 
 	@SuppressWarnings(Array("unchecked")) def refreshAllSprites(): Unit = {
-		if (nameToCoords != null && !nameToCoords.isEmpty && !sprites.isEmpty) return
+		if (nameToCoords != null && nameToCoords.nonEmpty && sprites.nonEmpty) return
 		val assetsDir = new File("assets")
-		val assets = new util.ArrayList[String]
+		var assets = Nil: List[String]
 		for (dir <- Objects.requireNonNull(assetsDir.listFiles)) {
-			assets.add(dir.getName)
+			assets ::= dir.getName
 		}
 
-		assets.forEach(asset => {
+		assets.foreach(asset => {
 			try {
 				val f = new File(assetsDir.getAbsolutePath + "/" + asset + "/textures/sprites")
 				assert(f.isDirectory || f.mkdirs)
-				val br = new BufferedReader(new InputStreamReader(new FileInputStream(new File(f, "sprites.json"))))
-				nameToCoords = new Gson().fromJson(br, classOf[util.Map[_, _]])
-				br.close()
-				nameToCoords.keySet.forEach(key => {
+				val json = Files.readString(new File(f, "sprites.json").toPath)
+				implicit val formats: DefaultFormats.type = DefaultFormats
+				nameToCoords = parse(json).extract[Map[String, List[List[Int]]]]
+				nameToCoords.keySet.foreach(key => {
 					try {
 						val is = new BufferedInputStream(new FileInputStream(new File(f, key + ".png")))
 						val img = ImageIO.read(is)
-						val cat = Category.create(key, new util.ArrayList[Sprite])
-						nameToCoords.get(key).forEach(list => {
-							val x = list.get(0).intValue
-							val y = list.get(1).intValue
+						val cat = Category.create(key, ListBuffer())
+						nameToCoords(key).foreach(list => {
+							val x = list.head.intValue
+							val y = list(1).intValue
 							val child = img.getSubimage(x, y, 16, 16)
-							new Sprite(child, cat, nameToCoords.get(key).indexOf(list))
+							new Sprite(child, cat, nameToCoords(key).toIndexedSeq.indexOf(list))
 						})
-						sprites.put(key, cat)
+						sprites += (key -> cat)
 					} catch {
 						case t: Throwable =>
 							System.err.println("Erreur lors de la lecture du sprite '" + key + "'")
@@ -102,7 +103,7 @@ object SpriteRegister {
 		})
 	}
 
-	def getCategory(name: String): Category = sprites.get(name)
+	def getCategory(name: String): Category = sprites(name)
 
-	def getAllCategories = new util.ArrayList[Category](sprites.values)
+	def getAllCategories: List[Category] = sprites.values.toList
 }
diff --git a/src/main/scala/fr/ynerant/leveleditor/client/main/Main.scala b/src/main/scala/fr/ynerant/leveleditor/client/main/Main.scala
index 8fcc208..e1a0df0 100644
--- a/src/main/scala/fr/ynerant/leveleditor/client/main/Main.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/client/main/Main.scala
@@ -1,19 +1,16 @@
 package fr.ynerant.leveleditor.client.main
 
+import java.awt._
+import java.awt.image.BufferedImage
+import java.io.{File, IOException}
+import java.net.{URISyntaxException, URL}
+import java.util.Locale
+
 import fr.ynerant.leveleditor.api.editor.EditorAPI
 import fr.ynerant.leveleditor.api.editor.sprites.SpriteRegister
 import fr.ynerant.leveleditor.frame.MainFrame
 import fr.ynerant.leveleditor.game.GameFrame
 import javax.swing._
-import java.awt._
-import java.awt.image.BufferedImage
-import java.io.File
-import java.io.IOException
-import java.net.URISyntaxException
-import java.net.URL
-import java.util.Locale
-
-import fr.ynerant.leveleditor.client.main.Main.DEV
 
 
 /**
diff --git a/src/main/scala/fr/ynerant/leveleditor/editor/CollidPanel.scala b/src/main/scala/fr/ynerant/leveleditor/editor/CollidPanel.scala
index bead2dd..d0e58f3 100644
--- a/src/main/scala/fr/ynerant/leveleditor/editor/CollidPanel.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/editor/CollidPanel.scala
@@ -1,9 +1,10 @@
 package fr.ynerant.leveleditor.editor
 
+import java.awt._
+import java.awt.image.BufferedImage
+
 import fr.ynerant.leveleditor.api.editor.Collision
 import javax.swing._
-import java.awt._
-import java.awt.image.BufferedImage
 
 
 @SerialVersionUID(-138754019431984881L)
@@ -21,8 +22,6 @@ object CollidPanel {
 
 @SerialVersionUID(-138754019431984881L)
 class CollidPanel(val frame: EditorFrame) extends JPanel {
-	def getMap: Map = frame.getMap
-
 	override def paintComponent(g: Graphics): Unit = {
 		g.fillRect(0, 0, getWidth, getHeight)
 		val img = getMap.getFont
@@ -31,7 +30,7 @@ class CollidPanel(val frame: EditorFrame) extends JPanel {
 		val width = img.getWidth * 2
 		val height = img.getHeight * 2
 		g.drawImage(getMap.getFont, x, y, width, height, null)
-		getMap.getAllCases.forEach(c => {
+		getMap.getAllCases.foreach(c => {
 			if (!CollidPanel.isEmpty(c.getCoucheOne.getImage)) {
 				g.drawImage(c.getCoucheOne.getImage, x + c.getPosX * 34 + 2, y + c.getPosY * 34 + 2, 32, 32, null)
 				if (!CollidPanel.isEmpty(c.getCoucheTwo.getImage)) {
@@ -42,8 +41,8 @@ class CollidPanel(val frame: EditorFrame) extends JPanel {
 			}
 		})
 
-		getMap.getAllCases.forEach(c => {
-			if (c.getCollision ne Collision.ANY) {
+		getMap.getAllCases.foreach(c => {
+			if (c.getCollision.equals(Collision.ANY)) {
 				val alpha = new BufferedImage(16, 16, BufferedImage.TYPE_INT_ARGB)
 				if (c.getCollision eq Collision.FULL) {
 					val grap = alpha.createGraphics
@@ -61,4 +60,6 @@ class CollidPanel(val frame: EditorFrame) extends JPanel {
 			}
 		})
 	}
+
+	def getMap: GMap = frame.getMap
 }
diff --git a/src/main/scala/fr/ynerant/leveleditor/editor/EditorFrame.scala b/src/main/scala/fr/ynerant/leveleditor/editor/EditorFrame.scala
index bbbe6f8..a7fa70d 100644
--- a/src/main/scala/fr/ynerant/leveleditor/editor/EditorFrame.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/editor/EditorFrame.scala
@@ -1,19 +1,18 @@
 package fr.ynerant.leveleditor.editor
 
-import fr.ynerant.leveleditor.api.editor.sprites.SpriteRegister
-import fr.ynerant.leveleditor.frame.listeners._
-import javax.swing._
-import javax.swing.event.ChangeEvent
-import javax.swing.event.ChangeListener
 import java.awt._
 import java.awt.event._
 import java.io.File
 
+import fr.ynerant.leveleditor.api.editor.sprites.SpriteRegister
 import fr.ynerant.leveleditor.api.editor.{EditorAPI, RawMap}
+import fr.ynerant.leveleditor.frame.listeners._
+import javax.swing._
+import javax.swing.event.{ChangeEvent, ChangeListener}
 
 
 @SerialVersionUID(-2705122356101556462L)
-class EditorFrame(val map: Map) extends JFrame("Level Editor") with ChangeListener with ActionListener with WindowListener {
+class EditorFrame(val map: GMap) extends JFrame("Level Editor") with ChangeListener with ActionListener with WindowListener {
 	final private val save = new JMenuItem("Sauvegarder")
 	final private val saveAs = new JMenuItem("Sauvegarder sous ...")
 	final private val exit = new JMenuItem("Quitter")
@@ -126,8 +125,8 @@ class EditorFrame(val map: Map) extends JFrame("Level Editor") with ChangeListen
 			couche2.repaint()
 			couche3.repaint()
 		}
-		SpriteRegister.getAllCategories.forEach(cat => {
-			cat.getSprites.forEach(spr => {
+		SpriteRegister.getAllCategories.foreach(cat => {
+			cat.getSprites.foreach(spr => {
 				val sprc1 = new SpriteComp(spr, 0)
 				val sprc2 = new SpriteComp(spr, 1)
 				val sprc3 = new SpriteComp(spr, 2)
@@ -170,7 +169,7 @@ class EditorFrame(val map: Map) extends JFrame("Level Editor") with ChangeListen
 		resources.getSelectedComponent.asInstanceOf[JScrollPane].getVerticalScrollBar.setValue(cursorPos)
 	}
 
-	def getMap: Map = map
+	def getMap: GMap = map
 
 	def getSelectedSprite: SpriteComp = selectedSprite
 
diff --git a/src/main/scala/fr/ynerant/leveleditor/editor/GMap.scala b/src/main/scala/fr/ynerant/leveleditor/editor/GMap.scala
new file mode 100644
index 0000000..2018ff1
--- /dev/null
+++ b/src/main/scala/fr/ynerant/leveleditor/editor/GMap.scala
@@ -0,0 +1,61 @@
+package fr.ynerant.leveleditor.editor
+
+import java.awt.image.BufferedImage
+
+import fr.ynerant.leveleditor.api.editor.sprites.SpriteRegister
+import fr.ynerant.leveleditor.api.editor.{Case, RawMap}
+
+
+object GMap {
+	private var cases = Nil: List[Case]
+}
+
+class GMap(val raw: RawMap) {
+	final private var frame = null: EditorFrame
+	final private var width = 0
+	final private var height = 0
+	private var casesMap = Map(): Map[Int, Map[Int, Case]]
+	final private var font = null: BufferedImage
+
+	GMap.cases = Nil
+	this.width = raw.getWidth
+	this.height = raw.getHeight
+	this.font = raw.getFont
+
+	raw.getCases.foreach(rc =>
+		GMap.cases = Case.create(rc.getPosX, rc.getPosY, SpriteRegister.getCategory(rc.getCoucheOne.getCategory).getSprites(rc.getCoucheOne.getIndex), SpriteRegister.getCategory(rc.getCoucheTwo.getCategory).getSprites(rc.getCoucheTwo.getIndex), SpriteRegister.getCategory(rc.getCoucheThree.getCategory).getSprites(rc.getCoucheThree.getIndex), rc.getCollision) :: GMap.cases
+	)
+
+	reorganizeMap()
+	frame = new EditorFrame(this)
+	getFrame.setVisible(true)
+
+	def getFrame: EditorFrame = frame
+
+	def getWidth: Int = width
+
+	def getHeight: Int = height
+
+	def getCase(x: Int, y: Int): Case = casesMap.getOrElse(x, Map())(y)
+
+	def getAllCases: List[Case] = {
+		val list = Nil: List[Case]
+		casesMap.values.foreach(l => list.appendedAll(l.values))
+		list
+	}
+
+	def getFont: BufferedImage = font
+
+	private def reorganizeMap(): Unit = {
+		for (i <- 0 until width) {
+			casesMap += (i -> Map())
+		}
+		GMap.cases.foreach(c => setCase(c.getPosX, c.getPosY, c))
+	}
+
+	def setCase(x: Int, y: Int, c: Case): Unit = {
+		var map = casesMap(x)
+		map = map + (y -> c)
+		casesMap = casesMap.updated(x, map)
+	}
+}
diff --git a/src/main/scala/fr/ynerant/leveleditor/editor/Map.scala b/src/main/scala/fr/ynerant/leveleditor/editor/Map.scala
deleted file mode 100644
index 75bd2c7..0000000
--- a/src/main/scala/fr/ynerant/leveleditor/editor/Map.scala
+++ /dev/null
@@ -1,60 +0,0 @@
-package fr.ynerant.leveleditor.editor
-
-import fr.ynerant.leveleditor.api.editor.sprites.SpriteRegister
-import java.awt.image.BufferedImage
-import java.util
-
-import fr.ynerant.leveleditor.api.editor.{Case, RawMap}
-
-
-object Map {
-	private var cases = null: util.ArrayList[Case]
-}
-
-class Map(val raw: RawMap) {
-	final private var frame = null: EditorFrame
-	final private var width = 0
-	final private var height = 0
-	final private val casesMap = new util.HashMap[Integer, util.Map[Integer, Case]]
-	final private var font = null: BufferedImage
-
-	Map.cases = new util.ArrayList[Case]
-	this.width = raw.getWidth
-	this.height = raw.getHeight
-	this.font = raw.getFont
-
-	raw.getCases.forEach(rc =>
-		Map.cases.add(Case.create(rc.getPosX, rc.getPosY, SpriteRegister.getCategory(rc.getCoucheOne.getCategory).getSprites.get(rc.getCoucheOne.getIndex), SpriteRegister.getCategory(rc.getCoucheTwo.getCategory).getSprites.get(rc.getCoucheTwo.getIndex), SpriteRegister.getCategory(rc.getCoucheThree.getCategory).getSprites.get(rc.getCoucheThree.getIndex), rc.getCollision))
-	)
-
-	reorganizeMap()
-	frame = new EditorFrame(this)
-	getFrame.setVisible(true)
-
-	def getFrame: EditorFrame = frame
-
-	def getWidth: Int = width
-
-	def getHeight: Int = height
-
-	def getCase(x: Int, y: Int): Case = casesMap.getOrDefault(x, new util.HashMap[Integer, Case]).get(y)
-
-	def setCase(x: Int, y: Int, c: Case): Unit = {
-		casesMap.get(x).put(y, c)
-	}
-
-	def getFont: BufferedImage = font
-
-	private def reorganizeMap(): Unit = {
-		for (i <- 0 until width) {
-			casesMap.put(i, new util.HashMap[Integer, Case])
-		}
-		Map.cases.forEach(c => setCase(c.getPosX, c.getPosY, c))
-	}
-
-	def getAllCases: util.List[Case] = {
-		val list = new util.ArrayList[Case]
-		casesMap.values.forEach(l => list.addAll(l.values()))
-		list
-	}
-}
diff --git a/src/main/scala/fr/ynerant/leveleditor/editor/MapPanel.scala b/src/main/scala/fr/ynerant/leveleditor/editor/MapPanel.scala
index 421b3b8..5146e49 100644
--- a/src/main/scala/fr/ynerant/leveleditor/editor/MapPanel.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/editor/MapPanel.scala
@@ -1,14 +1,13 @@
 package fr.ynerant.leveleditor.editor
 
-import javax.swing._
 import java.awt._
 import java.awt.image.BufferedImage
 
+import javax.swing._
+
 
 @SerialVersionUID(2629019576253690557L)
 class MapPanel(val frame: EditorFrame) extends JPanel {
-	def getMap: Map = frame.getMap
-
 	override def paintComponent(g: Graphics): Unit = {
 		g.fillRect(0, 0, getWidth, getHeight)
 		val img = getMap.getFont
@@ -17,7 +16,7 @@ class MapPanel(val frame: EditorFrame) extends JPanel {
 		val width = img.getWidth * 2
 		val height = img.getHeight * 2
 		g.drawImage(getMap.getFont, x, y, width, height, null)
-		getMap.getAllCases.forEach(c => { //		BufferedImage image;
+		getMap.getAllCases.foreach(c => { //		BufferedImage image;
 			if (!isEmpty(c.getCoucheOne.getImage)) g.drawImage(c.getCoucheOne.getImage, x + c.getPosX * 34 + 2, y + c.getPosY * 34 + 2, 32, 32, null)
 			/*	if (frame.getSelectedLayerIndex() != 0)
 						{
@@ -37,6 +36,8 @@ class MapPanel(val frame: EditorFrame) extends JPanel {
 		})
 	}
 
+	def getMap: GMap = frame.getMap
+
 	@SuppressWarnings(Array("BooleanMethodIsAlwaysInverted")) private def isEmpty(image: BufferedImage) = {
 		var allrgba = 0
 		for (x <- 0 until image.getWidth) {
diff --git a/src/main/scala/fr/ynerant/leveleditor/frame/listeners/CollidMapMouseListener.scala b/src/main/scala/fr/ynerant/leveleditor/frame/listeners/CollidMapMouseListener.scala
index a6cb33c..84b2b5e 100644
--- a/src/main/scala/fr/ynerant/leveleditor/frame/listeners/CollidMapMouseListener.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/frame/listeners/CollidMapMouseListener.scala
@@ -1,9 +1,8 @@
 package fr.ynerant.leveleditor.frame.listeners
 
-import fr.ynerant.leveleditor.api.editor.{Case, Collision}
-import java.awt.event.MouseAdapter
-import java.awt.event.MouseEvent
+import java.awt.event.{MouseAdapter, MouseEvent}
 
+import fr.ynerant.leveleditor.api.editor.Case
 import fr.ynerant.leveleditor.editor.{CollidPanel, EditorFrame}
 
 
@@ -16,11 +15,7 @@ class CollidMapMouseListener(val panel: CollidPanel, val frame: EditorFrame) ext
 		val y = panel.getHeight / 2 - map.getFont.getHeight
 		val c = map.getCase((event.getX - x + 2) / 34, (event.getY - y + 2) / 34)
 		if (c != null && event.getX - x >= 2 && event.getY - y >= 2) {
-			val colIndex = c.getCollision.id
-			var newColIndex = colIndex + 1
-			if (newColIndex >= Collision.values.size) newColIndex = 0
-			val col = Collision.apply(newColIndex)
-			val n = Case.create(c.getPosX, c.getPosY, c.getCoucheOne, c.getCoucheTwo, c.getCoucheThree, col)
+			val n = Case.create(c.getPosX, c.getPosY, c.getCoucheOne, c.getCoucheTwo, c.getCoucheThree, c.getCollision)
 			map.setCase((event.getX - x + 2) / 34, (event.getY - y + 2) / 34, n)
 			panel.repaint()
 		}
diff --git a/src/main/scala/fr/ynerant/leveleditor/frame/listeners/MapMouseListener.scala b/src/main/scala/fr/ynerant/leveleditor/frame/listeners/MapMouseListener.scala
index 099078e..7692b5c 100644
--- a/src/main/scala/fr/ynerant/leveleditor/frame/listeners/MapMouseListener.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/frame/listeners/MapMouseListener.scala
@@ -1,7 +1,6 @@
 package fr.ynerant.leveleditor.frame.listeners
 
-import java.awt.event.MouseAdapter
-import java.awt.event.MouseEvent
+import java.awt.event.{MouseAdapter, MouseEvent}
 
 import fr.ynerant.leveleditor.api.editor.Case
 import fr.ynerant.leveleditor.editor.{EditorFrame, MapPanel}
@@ -37,7 +36,7 @@ class MapMouseListener(val panel: MapPanel, val frame: EditorFrame) extends Mous
 			}
 		}
 		else if (frame.getSelectedPaintingMode == 1) {
-			getFrame.getMap.getAllCases.forEach(c => {
+			getFrame.getMap.getAllCases.foreach(c => {
 				val map = getFrame.getMap
 				if (getFrame.getSelectedSprite != null) {
 					if (getFrame.getSelectedSprite.getCouche - 1 > getFrame.getSelectedLayerIndex) return
diff --git a/src/main/scala/fr/ynerant/leveleditor/game/GameFrame.scala b/src/main/scala/fr/ynerant/leveleditor/game/GameFrame.scala
index f244593..635b2aa 100644
--- a/src/main/scala/fr/ynerant/leveleditor/game/GameFrame.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/game/GameFrame.scala
@@ -1,20 +1,17 @@
 package fr.ynerant.leveleditor.game
 
-import fr.ynerant.leveleditor.api.editor.{Collision, RawMap}
-import fr.ynerant.leveleditor.api.editor.sprites.SpriteRegister
-import fr.ynerant.leveleditor.game.mobs.Mob
-import fr.ynerant.leveleditor.game.towers.AutoTower
-import fr.ynerant.leveleditor.game.towers.BasicTower
-import fr.ynerant.leveleditor.game.towers.NullTower
-import fr.ynerant.leveleditor.game.towers.Tower
-import javax.swing._
+import java.awt.event.{MouseEvent, MouseListener}
 import java.awt._
-import java.awt.event.MouseEvent
-import java.awt.event.MouseListener
-import java.util
 import java.util.Random
 
+import fr.ynerant.leveleditor.api.editor.sprites.SpriteRegister
+import fr.ynerant.leveleditor.api.editor.{Collision, RawMap}
 import fr.ynerant.leveleditor.editor.CollidPanel
+import fr.ynerant.leveleditor.game.mobs.Mob
+import fr.ynerant.leveleditor.game.towers.{AutoTower, BasicTower, NullTower, Tower}
+import javax.swing._
+
+import scala.collection.mutable.ListBuffer
 
 
 class GameFrame(val map: RawMap) extends JFrame("Jeu") {
@@ -22,8 +19,8 @@ class GameFrame(val map: RawMap) extends JFrame("Jeu") {
 	private var round = 0
 	private var hp = 5
 	private var reward = 20
-	final private val mobs = new util.ArrayList[Mob]
-	final private val towers = new util.ArrayList[Tower]
+	private var mobs = ListBuffer[Mob]()
+	private var towers = ListBuffer[Tower]()
 	final private var basicTower = null: JRadioButton
 	final private var nullTower = null: JRadioButton
 	final private var autoTower = null: JRadioButton
@@ -74,7 +71,7 @@ class GameFrame(val map: RawMap) extends JFrame("Jeu") {
 	setVisible(true)
 	new Thread(() => {
 		while ( {
-			hp > 0 && (round < 4 || !mobs.isEmpty)
+			hp > 0 && (round < 4 || mobs.nonEmpty)
 		}) {
 			tick()
 			try Thread.sleep(50L)
@@ -92,25 +89,25 @@ class GameFrame(val map: RawMap) extends JFrame("Jeu") {
 		if (mobs.isEmpty && round < 4) {
 			round += 1
 			val nb_mobs = round * (RANDOM.nextInt(16) + 1)
-			for (i <- 1 to nb_mobs) {
+			for (_ <- 1 to nb_mobs) {
 				val mob = Mob.getRandomMob
 				do mob.move(RANDOM.nextInt(getMap.getWidth / 16), RANDOM.nextInt(getMap.getHeight / 16)) while ( {
-					getMap.getCase(mob.getX, mob.getY).getCollision != Collision.ANY
+					!getMap.getCase(mob.getX, mob.getY).getCollision.equals(Collision.ANY)
 				})
 				getMap.getCase(mob.getX, mob.getY).setCollision(Collision.PARTIAL)
-				mobs.add(mob)
+				mobs += mob
 			}
 		}
-		towers.forEach(tower => {
-			tower.filterDetectedMobs(mobs).forEach(mob => {
+		towers.foreach(tower => {
+			tower.filterDetectedMobs(mobs).foreach(mob => {
 				mob.hit(tower.getDamagePerShot)
 			})
 		})
-		new util.ArrayList[Mob](mobs).forEach(mob => {
+		mobs.foreach(mob => {
 			getMap.getCase(mob.getX, mob.getY).setCollision(Collision.ANY)
 			mob.tick(this)
 			if (mob.getX < 0 || mob.isDead) {
-				mobs.remove(mob)
+				mobs -= mob
 				if (mob.getX < 0) {
 					hp -= 1
 					if (hp == 0) {
@@ -138,36 +135,6 @@ class GameFrame(val map: RawMap) extends JFrame("Jeu") {
 	class Grid() extends JComponent with MouseListener {
 		addMouseListener(this)
 
-		override protected def paintComponent(_g: Graphics): Unit = {
-			val g = _g.asInstanceOf[Graphics2D]
-			if (getMap.getFont != null) g.drawImage(getMap.getFont, null, null)
-			SpriteRegister.refreshAllSprites()
-			val SPRITE_SIZE = 32
-			getMap.getCases.forEach(c => {
-				val s1 = SpriteRegister.getCategory(c.getCoucheOne.getCategory).getSprites.get(c.getCoucheOne.getIndex)
-				val s2 = SpriteRegister.getCategory(c.getCoucheTwo.getCategory).getSprites.get(c.getCoucheTwo.getIndex)
-				val s3 = SpriteRegister.getCategory(c.getCoucheThree.getCategory).getSprites.get(c.getCoucheThree.getIndex)
-				g.drawImage(s1.getImage, SPRITE_SIZE * c.getPosX, SPRITE_SIZE * c.getPosY, SPRITE_SIZE, SPRITE_SIZE, Color.white, null)
-				if (!CollidPanel.isEmpty(s2.getImage)) g.drawImage(s2.getImage, SPRITE_SIZE * c.getPosX, SPRITE_SIZE * c.getPosY, SPRITE_SIZE, SPRITE_SIZE, null, null)
-				if (!CollidPanel.isEmpty(s3.getImage)) g.drawImage(s3.getImage, SPRITE_SIZE * c.getPosX, SPRITE_SIZE * c.getPosY, SPRITE_SIZE, SPRITE_SIZE, null, null)
-			})
-			new util.ArrayList[Mob](mobs).forEach(mob => {
-				val s = mob.getSprite
-				g.drawImage(s.getImage, SPRITE_SIZE * mob.getX, SPRITE_SIZE * mob.getY, SPRITE_SIZE, SPRITE_SIZE, null, null)
-			})
-			towers.forEach(tower => {
-				val s = tower.getSprite
-				g.drawImage(s.getImage, SPRITE_SIZE * tower.getX, SPRITE_SIZE * tower.getY, SPRITE_SIZE, SPRITE_SIZE, null, null)
-			})
-			repaint()
-		}
-
-		override def mouseClicked(event: MouseEvent): Unit = {
-		}
-
-		override def mousePressed(event: MouseEvent): Unit = {
-		}
-
 		override def mouseReleased(event: MouseEvent): Unit = {
 			val x = event.getX / 32
 			val y = event.getY / 32
@@ -177,10 +144,41 @@ class GameFrame(val map: RawMap) extends JFrame("Jeu") {
 			else null
 			if (tower == null || tower.getPrice > reward) return
 			val c = getMap.getCase(x, y)
-			if (c == null || (c.getCollision ne Collision.ANY)) return
+			println(x + ", " + y + ", " + tower + ", " + c)
+			if (c == null || !c.getCollision.equals(Collision.ANY)) return
 			c.setCollision(Collision.FULL)
 			reward -= tower.getPrice
-			towers.add(tower)
+			towers += tower
+		}
+
+		override def mouseClicked(event: MouseEvent): Unit = {
+		}
+
+		override def mousePressed(event: MouseEvent): Unit = {
+		}
+
+		override protected def paintComponent(_g: Graphics): Unit = {
+			val g = _g.asInstanceOf[Graphics2D]
+			if (getMap.getFont != null) g.drawImage(getMap.getFont, null, null)
+			SpriteRegister.refreshAllSprites()
+			val SPRITE_SIZE = 32
+			getMap.getCases.foreach(c => {
+				val s1 = SpriteRegister.getCategory(c.getCoucheOne.getCategory).getSprites(c.getCoucheOne.getIndex)
+				val s2 = SpriteRegister.getCategory(c.getCoucheTwo.getCategory).getSprites(c.getCoucheTwo.getIndex)
+				val s3 = SpriteRegister.getCategory(c.getCoucheThree.getCategory).getSprites(c.getCoucheThree.getIndex)
+				g.drawImage(s1.getImage, SPRITE_SIZE * c.getPosX, SPRITE_SIZE * c.getPosY, SPRITE_SIZE, SPRITE_SIZE, Color.white, null)
+				if (!CollidPanel.isEmpty(s2.getImage)) g.drawImage(s2.getImage, SPRITE_SIZE * c.getPosX, SPRITE_SIZE * c.getPosY, SPRITE_SIZE, SPRITE_SIZE, null, null)
+				if (!CollidPanel.isEmpty(s3.getImage)) g.drawImage(s3.getImage, SPRITE_SIZE * c.getPosX, SPRITE_SIZE * c.getPosY, SPRITE_SIZE, SPRITE_SIZE, null, null)
+			})
+			mobs.foreach(mob => {
+				val s = mob.getSprite
+				g.drawImage(s.getImage, SPRITE_SIZE * mob.getX, SPRITE_SIZE * mob.getY, SPRITE_SIZE, SPRITE_SIZE, null, null)
+			})
+			towers.foreach(tower => {
+				val s = tower.getSprite
+				g.drawImage(s.getImage, SPRITE_SIZE * tower.getX, SPRITE_SIZE * tower.getY, SPRITE_SIZE, SPRITE_SIZE, null, null)
+			})
+			repaint()
 		}
 
 		override def mouseEntered(event: MouseEvent): Unit = {
diff --git a/src/main/scala/fr/ynerant/leveleditor/game/mobs/Mob.scala b/src/main/scala/fr/ynerant/leveleditor/game/mobs/Mob.scala
index 1579338..cda4f5e 100644
--- a/src/main/scala/fr/ynerant/leveleditor/game/mobs/Mob.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/game/mobs/Mob.scala
@@ -1,12 +1,11 @@
 package fr.ynerant.leveleditor.game.mobs
 
-import fr.ynerant.leveleditor.api.editor.sprites.Sprite
-import fr.ynerant.leveleditor.api.editor.sprites.SpriteRegister
-import fr.ynerant.leveleditor.game.GameFrame
 import java.util
 import java.util.Random
 
 import fr.ynerant.leveleditor.api.editor.RawCase
+import fr.ynerant.leveleditor.api.editor.sprites.{Sprite, SpriteRegister}
+import fr.ynerant.leveleditor.game.GameFrame
 
 
 object Mob {
@@ -38,7 +37,7 @@ abstract class Mob() {
 	def getName: String
 
 	def getSprite: Sprite = {
-		if (sprite == null) sprite = SpriteRegister.getCategory(getName).getSprites.get(0)
+		if (sprite == null) sprite = SpriteRegister.getCategory(getName).getSprites.head
 		sprite
 	}
 
@@ -77,17 +76,17 @@ abstract class Mob() {
 				return
 			}
 
-			val visited = new util.ArrayList[RawCase]
+			var visited = Nil: List[RawCase]
 			val queue = new util.ArrayDeque[RawCase]
-			val pred = new util.HashMap[RawCase, RawCase]
+			var pred = Map(): Map[RawCase, RawCase]
 			var last = null: RawCase
 			queue.add(current)
 			while (!queue.isEmpty) {
 				val visiting = queue.poll
-				visited.add(visiting)
-				game.getMap.getNeighbours(visiting).forEach(neighbour => {
+				visited ::= visiting
+				game.getMap.getNeighbours(visiting).foreach(neighbour => {
 					if (neighbour != null && !visited.contains(neighbour)) {
-						pred.put(neighbour, visiting)
+						pred += (neighbour -> visiting)
 						queue.add(neighbour)
 						if (neighbour.getPosX == 0) {
 							last = neighbour
@@ -97,7 +96,7 @@ abstract class Mob() {
 					}
 				})
 				if (last != null) {
-					while (pred.get(last) != current) last = pred.get(last)
+					while (pred(last) != current) last = pred(last)
 					move(last.getPosX, last.getPosY)
 				}
 			}
diff --git a/src/main/scala/fr/ynerant/leveleditor/game/towers/AutoTower.scala b/src/main/scala/fr/ynerant/leveleditor/game/towers/AutoTower.scala
index 9481bb5..dbfd876 100644
--- a/src/main/scala/fr/ynerant/leveleditor/game/towers/AutoTower.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/game/towers/AutoTower.scala
@@ -1,7 +1,6 @@
 package fr.ynerant.leveleditor.game.towers
 
 import fr.ynerant.leveleditor.game.mobs.Mob
-import java.util
 
 
 class AutoTower(override val x: Int, override val y: Int) extends Tower(x, y) {
@@ -13,5 +12,5 @@ class AutoTower(override val x: Int, override val y: Int) extends Tower(x, y) {
 
 	override def getPrice = 142
 
-	override private[towers] def _filterDetectedMobs(mobs: util.Collection[Mob]) = mobs
+	override private[towers] def _filterDetectedMobs(mobs: Iterable[Mob]) = mobs
 }
diff --git a/src/main/scala/fr/ynerant/leveleditor/game/towers/BasicTower.scala b/src/main/scala/fr/ynerant/leveleditor/game/towers/BasicTower.scala
index d095341..a5782f3 100644
--- a/src/main/scala/fr/ynerant/leveleditor/game/towers/BasicTower.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/game/towers/BasicTower.scala
@@ -1,7 +1,6 @@
 package fr.ynerant.leveleditor.game.towers
 
 import fr.ynerant.leveleditor.game.mobs.Mob
-import java.util
 
 
 class BasicTower(override val x: Int, override val y: Int) extends Tower(x, y) {
@@ -13,11 +12,7 @@ class BasicTower(override val x: Int, override val y: Int) extends Tower(x, y) {
 
 	override def getPrice = 10
 
-	override private[towers] def _filterDetectedMobs(mobs: util.Collection[Mob]) = {
-		val filtered = new util.ArrayList[Mob]
-		mobs.forEach(mob => {
-			if ((mob.getX == getX || mob.getY == getY) && Math.abs(mob.getX - getX) <= 3 && Math.abs(mob.getY - getY) <= 3) filtered.add(mob)
-		})
-		filtered
+	override private[towers] def _filterDetectedMobs(mobs: Iterable[Mob]) = {
+		mobs.filter(mob => (mob.getX == getX || mob.getY == getY) && Math.abs(mob.getX - getX) <= 3 && Math.abs(mob.getY - getY) <= 3)
 	}
 }
diff --git a/src/main/scala/fr/ynerant/leveleditor/game/towers/NullTower.scala b/src/main/scala/fr/ynerant/leveleditor/game/towers/NullTower.scala
index e24814d..9714172 100644
--- a/src/main/scala/fr/ynerant/leveleditor/game/towers/NullTower.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/game/towers/NullTower.scala
@@ -1,7 +1,6 @@
 package fr.ynerant.leveleditor.game.towers
 
 import fr.ynerant.leveleditor.game.mobs.Mob
-import java.util
 
 
 class NullTower(override val x: Int, override val y: Int) extends Tower(x, y) {
@@ -13,5 +12,5 @@ class NullTower(override val x: Int, override val y: Int) extends Tower(x, y) {
 
 	override def getPrice = 5
 
-	override private[towers] def _filterDetectedMobs(mobs: util.Collection[Mob]) = new util.ArrayList[Mob]
+	override private[towers] def _filterDetectedMobs(mobs: Iterable[Mob]) = Nil
 }
diff --git a/src/main/scala/fr/ynerant/leveleditor/game/towers/Tower.scala b/src/main/scala/fr/ynerant/leveleditor/game/towers/Tower.scala
index 431e690..2884076 100644
--- a/src/main/scala/fr/ynerant/leveleditor/game/towers/Tower.scala
+++ b/src/main/scala/fr/ynerant/leveleditor/game/towers/Tower.scala
@@ -1,18 +1,17 @@
 package fr.ynerant.leveleditor.game.towers
 
-import fr.ynerant.leveleditor.api.editor.sprites.Sprite
-import fr.ynerant.leveleditor.api.editor.sprites.SpriteRegister
-import fr.ynerant.leveleditor.game.mobs.Mob
-import java.util
 import java.util.Random
 
+import fr.ynerant.leveleditor.api.editor.sprites.{Sprite, SpriteRegister}
+import fr.ynerant.leveleditor.game.mobs.Mob
+
 
 object Tower {
 	private val RANDOM = new Random
 }
 
 abstract class Tower(val x: Int, val y: Int) {
-	final private val sprite = SpriteRegister.getCategory(getName).getSprites.get(0)
+	final private val sprite = SpriteRegister.getCategory(getName).getSprites.head
 	private var remainingTicks = 0L
 
 	def getSprite: Sprite = sprite
@@ -25,17 +24,17 @@ abstract class Tower(val x: Int, val y: Int) {
 
 	def getPrice: Int
 
-	private[towers] def _filterDetectedMobs(mobs: util.Collection[Mob]): util.Collection[Mob]
-
-	def filterDetectedMobs(mobs: util.Collection[Mob]): util.Collection[Mob] = if (remainingTicks > 0) {
+	def filterDetectedMobs(mobs: Iterable[Mob]): Iterable[Mob] = if (remainingTicks > 0) {
 		remainingTicks -= 1
-		new util.ArrayList[Mob]
+		Nil
 	}
 	else {
 		remainingTicks = getPeriod
 		_filterDetectedMobs(mobs)
 	}
 
+	private[towers] def _filterDetectedMobs(mobs: Iterable[Mob]): Iterable[Mob]
+
 	def getX: Int = x
 
 	def getY: Int = y