Add levelling up mechanics through experience gained via killing enemies

src/core/config/GameConfig.ts

@@ -1,9 +1,19 @@
 export const GAME_CONFIG = {
   player: {
-    initialStats: { maxHp: 20, hp: 20, attack: 5, defense: 2 },
+    initialStats: { 
+      maxHp: 20, 
+      hp: 20, 
+      attack: 5, 
+      defense: 2,
+      level: 1,
+      exp: 0,
+      expToNextLevel: 10
+    },
     speed: 100,
     viewRadius: 8
   },
+
+
   
   map: {
     width: 60,
@@ -17,18 +27,26 @@ export const GAME_CONFIG = {
   },
   
   enemy: {
-    baseHpPerLevel: 2,
     baseHp: 8,
     baseAttack: 3,
-    attackPerTwoLevels: 1,
     minSpeed: 80,
     maxSpeed: 130,
-    maxDefense: 2,
-    baseCountPerLevel: 1,
+    baseHpPerFloor: 5,
+    attackPerTwoFloors: 1,
     baseCount: 3,
-    randomBonus: 4
+    baseCountPerFloor: 3,
+    ratExp: 5,
+    batExp: 8
   },
   
+  leveling: {
+    baseExpToNextLevel: 10,
+    expMultiplier: 1.5,
+    hpGainPerLevel: 5,
+    attackGainPerLevel: 1
+  },
+
+  
   rendering: {
     tileSize: 16,
     cameraZoom: 2,
@@ -38,6 +56,9 @@ export const GAME_CONFIG = {
     playerColor: 0x66ff66,
     enemyColor: 0xff6666,
     pathPreviewColor: 0x3355ff,
+    expOrbColor: 0x33ccff,
+    expTextColor: 0x33ccff,
+    levelUpColor: 0xffff00,
     fogAlphaFloor: 0.15,
     fogAlphaWall: 0.35,
     visibleMinAlpha: 0.35,
@@ -45,6 +66,7 @@ export const GAME_CONFIG = {
     visibleStrengthFactor: 0.65
   },
 
+
   terrain: {
     empty: 1,
     wall: 4,