feat: Add main game scene with core logic, manager initialization, UI setup, and an in-game message bar.

scripts/managers/special_tiles_manager.gd

@@ -269,10 +269,17 @@ func spawn_powerups_around(center: Vector2i, force_powerups: bool = true):
 		for y in range(-radius, radius + 1):
 			var pos = center + Vector2i(x, y)
 			if enhanced_gridmap.is_position_valid(pos):
-				# Random chance
-				if rng.randf() > 0.4: continue
+				# Random chance to spawn ANYTHING at this spot (keep density reasonable)
+				if rng.randf() > 0.5: continue
+				
+				var item_id: int
+				# 70% Chance for PowerUp (11-14)
+				if rng.randf() < 0.7:
+					item_id = rng.randi_range(11, 14)
+				else:
+					# 30% Chance for Normal Tile (7-10)
+					item_id = rng.randi_range(7, 10)
 				
-				var item_id = rng.randi_range(11, 14) # 11-14 are the new powerups
 				var cell = Vector3i(pos.x, 1, pos.y)
 				
 				if player.is_multiplayer_authority():