diff --git a/src/settings.py b/src/settings.py
index 428d28e..476b6d6 100644
--- a/src/settings.py
+++ b/src/settings.py
@@ -11,17 +11,16 @@ DESK_HEIGHT = 40
 DOOR_WIDTH = 20
 DOOR_HEIGHT = 100
 DOOR_BORDER_WIDTH = 3
+DOOR_HP = 100
 
 COLOR_DOOR_BEIGE = (245, 245, 220)
 COLOR_DOOR_BORDER = (100, 90, 80)
 
-
 # --- PLAYER ---
 # Players Constants / Settings
 # Valid movement/animation directions.
 Direction = Literal["down", "left", "right", "up"]
 
-
 # --- SPRITE ---
 # Sprite files are grouped by direction.
 # Example: "down" uses sprite_01.png, sprite_02.png, sprite_03.png.
@@ -36,26 +35,22 @@ DIRECTION_FRAMES: Mapping[Direction, Tuple[int, int, int]] = {
 DEFAULT_SPRITE_HEIGHT: int = 138
 DEFAULT_FRAME_TIME: float = 0.16
 
-
 # --- ECTS ---
-START_ECTS_VALUE = 1        # how many ECTS are generated at the beginning
-ECTS_UPDATE_INTERVAL = 1000     # time in ms (1000 = 1 sec)
+START_ECTS_VALUE = 1  # how many ECTS are generated at the beginning
+ECTS_UPDATE_INTERVAL = 1000  # time in ms (1000 = 1 sec)
 
 BEER_BOTTLE_ECTS_VALUE = 2
 BEER_COST = 50
 
-
 # --- BUTTONS ---
 COLOR_BUTTON = (0, 255, 0)
 COLOR_BUTTON_HOVER = (200, 255, 0)
 
-
 # --- STARTSCREEN ---
 COLOR_STARTSCREEN_BACKGROUND = (0, 0, 0)
 COLOR_STARTSCREEN_FONT_TITLE = (0, 255, 0)
 COLOR_STARTSCREEN_FONT_LABEL = (0, 255, 255)
 
-
 # --- ENDSCREEN ---
 COLOR_ENDSCREEN_BACKGROUND = (0, 0, 0)
 COLOR_ENDSCREEN_TEXT = (255, 255, 255)
@@ -63,26 +58,22 @@ COLOR_ENDSCREEN_WIN = (0, 255, 0)
 COLOR_ENDSCREEN_LOSE = (255, 0, 0)
 FONT_ENDSCREEN = "Arial"
 
-
 # --- COFFEE ---
 COFFEE_COST = 30
 COFFEE_HEAL_VALUE = 30
 
-
 # --- TOWER ---
-TOWER_COST = 150
-PROJECTILE_DMG = 15
+TOWER_COST = 10
+PROJECTILE_DMG = 7
 PROJECTILE_SPEED = 7
 COLOR_PROJECTILE = (200, 200, 0)
-TOWER_TIMER = 30000             # how long the tower stays and attack before it disappears
-
+TOWER_TIMER = 30000  # how long the tower stays and attack before it disappears
 
 # --- ITEM SPAWN TIMER ---
-ITEM_SPAWN_INTERVAL = 5000      # ms until a new item spawns
-ITEM_SHOPPING_TIMER = 10000     # how long you have time to buy items before they despawn
+ITEM_SPAWN_INTERVAL = 5000  # ms until a new item spawns
+ITEM_SHOPPING_TIMER = 10000  # how long you have time to buy items before they despawn
 ITEM_SIZE = 30
 
-
 # --- ZOMBIE ---
 ZOMBIE_EASY_HP = 30
 ZOMBIE_EASY_DMG = 3
@@ -93,6 +84,13 @@ ZOMBIE_MEDIUM_DMG = 7
 ZOMBIE_HARD_HP = 120
 ZOMBIE_HARD_DMG = 12
 
+# --- MONSTERS ---
+MONSTER_HP = ZOMBIE_MEDIUM_HP
+MONSTER_MAX_COUNT = 1
+MONSTER_SPAWN_INTERVAL = 8000  # ms until a replacement monster spawns
+MONSTER_SPEED = 90.0
+MONSTER_DOOR_DAMAGE = ZOMBIE_MEDIUM_DMG
+MONSTER_ATTACK_INTERVAL = 1000  # ms between door attacks
 
 # --- HUD ---
 HUD_FONT = "Arial"
@@ -114,8 +112,8 @@ PLAYER_SPEED = 180.0
 DEMO_ACTOR_HEIGHT = tile_size * 3
 FPS = 60
 
-HUD_X_OFFSET = 20               # left startpoint for texts
-HUD_BAR_X = 150                 # left startpoint for hp bars
+HUD_X_OFFSET = 20  # left startpoint for texts
+HUD_BAR_X = 150  # left startpoint for hp bars
 
 HUD_Y_DOOR = 20
 HUD_Y_ZOMBIE = 50