diff --git a/dungeonbattle/interfaces.py b/dungeonbattle/interfaces.py
index 02bf5eb..a312d34 100644
--- a/dungeonbattle/interfaces.py
+++ b/dungeonbattle/interfaces.py
@@ -3,6 +3,10 @@ from enum import Enum
 
 
 class Map:
+    """
+    Object that represents a Map with its width, height
+    and the whole tiles, with their custom properties.
+    """
     width: int
     height: int
     tiles: list
@@ -14,12 +18,18 @@ class Map:
 
     @staticmethod
     def load(filename: str):
+        """
+        Read a file that contains the content of a map, and build a Map object.
+        """
         with open(filename, "r") as f:
             file = f.read()
         return Map.load_from_string(file)
 
     @staticmethod
     def load_from_string(content: str):
+        """
+        Load a map represented by its characters and build a Map object.
+        """
         lines = content.split("\n")
         lines = [line for line in lines if line]
         height = len(lines)
@@ -29,6 +39,10 @@ class Map:
         return Map(width, height, tiles)
 
     def draw_string(self) -> str:
+        """
+        Draw the current map as a string object that can be rendered
+        in the window.
+        """
         return "\n".join("".join(tile.value for tile in line)
                          for line in self.tiles)
 
@@ -42,6 +56,9 @@ class Tile(Enum):
         return self == Tile.WALL
 
     def can_walk(self) -> bool:
+        """
+        Check if an entity (player or not) can move in this tile.
+        """
         return not self.is_wall()
 
 
diff --git a/dungeonbattle/interfaces_test.py b/dungeonbattle/interfaces_test.py
index dc8932a..34a50f9 100644
--- a/dungeonbattle/interfaces_test.py
+++ b/dungeonbattle/interfaces_test.py
@@ -5,6 +5,9 @@ from dungeonbattle.interfaces import Map
 
 class TestInterfaces(unittest.TestCase):
     def test_map(self) -> None:
+        """
+        Create a map and check that it is well parsed.
+        """
         m = Map.load_from_string(".#\n#.\n")
         self.assertEqual(m.width, 2)
         self.assertEqual(m.height, 2)
diff --git a/dungeonbattle/proof_of_concept.py b/dungeonbattle/proof_of_concept.py
index 8db5aeb..2034cbf 100644
--- a/dungeonbattle/proof_of_concept.py
+++ b/dungeonbattle/proof_of_concept.py
@@ -1,22 +1,29 @@
-#!/usr/bin/env python
 from .interfaces import Map
 from .term_manager import TermManager
 
 
 def proof_of_concept() -> None:
+    """
+    Read an example map, parse it, then the (squirrel) player can move freely.
+    """
+    # Load the example map
     m = Map.load("example_map.txt")
 
+    # Create the context manager to manipulate the screen
     with TermManager() as term_manager:
         stdscr = term_manager.screen
 
+        # Draw the full map
         stdscr.addstr(0, 0, m.draw_string())
         stdscr.refresh()
 
         cur = [1, 6]    # (y,x)
+        # We are a squirrel
         stdscr.addstr(1, 6, '🐿️')
         stdscr.refresh()
 
         while True:
+            # Get movements of the user
             key = stdscr.getkey()
             stdscr.addstr(cur[0], cur[1], '.')
             next_pos = cur[:]
@@ -28,8 +35,11 @@ def proof_of_concept() -> None:
                 next_pos[1] = cur[1] - 1
             if key == 'd' or key == 'KEY_RIGHT':
                 next_pos[1] = cur[1] + 1
+            # Check if we stay in the bounds
             if 0 <= next_pos[0] < m.height and 0 <= next_pos[0] < m.width:
                 next_tile = m.tiles[next_pos[0]][next_pos[1]]
+                # Check if the new position is valid
                 if next_tile.can_walk():
                     cur = next_pos
+            # Draw the squirrel
             stdscr.addstr(cur[0], cur[1], '🐿️')