add kick system

scripts/Enemy.gd

@@ -18,6 +18,7 @@ var chain_factor: float = 0.65
 var stun_time: float = 0.5
 var base_scale: float = 1.0
 var wave_num: int = 1
+var damage_modifier: float = 0.75
 
 var state: State = State.CHASING
 var fly_vel: Vector3 = Vector3.ZERO
@@ -140,14 +141,18 @@ func _fly(delta: float) -> void:
 			hit_wall = true
 			break
 		elif col3d.is_in_group("enemies") and col3d != self:
-			var other: Node = col3d		
-			if speed_now >= 3.0 and other.get("enemy_level") == enemy_level and other.get("is_upgrading") == false and is_upgrading == false:
-				_start_merge(other)
-			else:
+			var merged := KickSystem.resolve(self, col3d, fly_vel)
+			if not merged and is_instance_valid(col3d):
 				var chain_dir := col3d.global_position - global_position
 				chain_dir.y = 0.0
 				if chain_dir.length() > 0.01:
 					col3d.call("receive_kick", chain_dir.normalized(), speed_now * chain_factor)
+		elif col3d.is_in_group("rocks"):
+			KickSystem.resolve(self, col3d, fly_vel)
+			var rock_dir := col3d.global_position - global_position
+			rock_dir.y = 0.0
+			if rock_dir.length() > 0.01:
+				col3d.call("receive_kick", rock_dir.normalized(), speed_now * 0.5)
 		elif col3d.is_in_group("player"):
 			col3d.call("take_damage", int(speed_now * 0.6))
 
@@ -166,6 +171,19 @@ func _stun_tick(delta: float) -> void:
 	if stun_timer <= 0.0:
 		_enter_chase()
 
+func can_merge_with(other: Node3D, collision_speed: float) -> bool:
+	return (collision_speed >= 3.0
+		and other.get("enemy_type") == enemy_type
+		and other.get("enemy_level") == enemy_level
+		and not is_upgrading
+		and not other.get("is_upgrading"))
+
+func do_merge_with(other: Node3D) -> void:
+	_start_merge(other)
+
+func apply_collision_damage(dmg: float) -> void:
+	_take_hit(int(dmg))
+
 func receive_kick(direction: Vector3, force: float) -> void:
 	if state == State.DEAD:
 		return

scripts/KickSystem.gd

@@ -0,0 +1,41 @@
+class_name KickSystem
+
+# Deduplication: each (A,B) pair resolved once per physics frame
+static var _frame: int = -1
+static var _pairs: Dictionary = {}
+
+# Called by a flying kickable when it detects another kickable.
+# Returns true if a merge happened (both objects will despawn).
+static func resolve(owner: Node3D, other: Node3D, owner_vel: Vector3) -> bool:
+	var f := Engine.get_physics_frames()
+	if f != _frame:
+		_frame = f
+		_pairs.clear()
+
+	var id_lo := mini(owner.get_instance_id(), other.get_instance_id())
+	var id_hi := maxi(owner.get_instance_id(), other.get_instance_id())
+	var key   := str(id_lo) + "_" + str(id_hi)
+	if _pairs.has(key):
+		return false
+	_pairs[key] = true
+
+	var other_vel: Vector3 = other.get("fly_vel") if other.get("fly_vel") != null else Vector3.ZERO
+	var speed_a := Vector2(owner_vel.x, owner_vel.z).length()
+	var speed_b := Vector2(other_vel.x, other_vel.z).length()
+	var collision_speed := speed_a + speed_b
+
+	# ── 1. Merge ──────────────────────────────────────────────────────────────
+	if owner.has_method("can_merge_with") and owner.call("can_merge_with", other, collision_speed):
+		owner.call("do_merge_with", other)
+		return true
+
+	# ── 2. Damage ─────────────────────────────────────────────────────────────
+	var mod_a: float = owner.get("damage_modifier") if owner.get("damage_modifier") != null else 0.0
+	var mod_b: float = other.get("damage_modifier") if other.get("damage_modifier") != null else 0.0
+
+	if is_instance_valid(other) and other.has_method("apply_collision_damage") and mod_a > 0.0:
+		other.call("apply_collision_damage", collision_speed * mod_a)
+	if is_instance_valid(owner) and owner.has_method("apply_collision_damage") and mod_b > 0.0:
+		owner.call("apply_collision_damage", collision_speed * mod_b)
+
+	return false

scripts/KickSystem.gd.uid

@@ -0,0 +1 @@
+uid://ddke1n1a07f8x

scripts/Rock.gd

@@ -4,15 +4,14 @@ enum State { IDLE, FLYING }
 
 const AIR_FRICTION  := 0.84
 const MIN_SPEED     := 0.5
-const DAMAGE_MULT   := 0.9
 const WALL_BOUNCE   := 0.5
 const WALL_SELF_DMG := 0.6
-const HIT_SELF_DMG  := 0.4
 
 var state: State = State.IDLE
 var fly_vel: Vector3 = Vector3.ZERO
 var health: float = 60.0
 var dead: bool = false
+var damage_modifier: float = 1.25
 
 @onready var mesh_node: MeshInstance3D = $RockMesh
 var rock_mat: StandardMaterial3D
@@ -25,6 +24,12 @@ func _ready() -> void:
 	rock_mat = mesh_node.material_override.duplicate() as StandardMaterial3D
 	mesh_node.material_override = rock_mat
 
+func can_merge_with(_other: Node3D, _speed: float) -> bool:
+	return false
+
+func apply_collision_damage(dmg: float) -> void:
+	_take_damage(dmg)
+
 func receive_kick(direction: Vector3, force: float) -> void:
 	fly_vel = direction * force
 	fly_vel.y = 0.0
@@ -57,14 +62,16 @@ func _fly(delta: float) -> void:
 			_take_damage(speed_now * WALL_SELF_DMG)
 			handled = true
 			break
-		elif col3d.is_in_group("enemies"):
-			var to_enemy := col3d.global_position - global_position
-			to_enemy.y = 0.0
-			var dir := to_enemy.normalized() if to_enemy.length() > 0.01 else (fly_vel.normalized() if fly_vel.length() > 0.01 else Vector3.FORWARD)
-			col3d.call("_take_hit", int(speed_now * DAMAGE_MULT))
-			col3d.call("receive_kick", dir, speed_now * 0.65)
+		elif col3d.is_in_group("enemies") or col3d.is_in_group("rocks"):
+			if col3d == self:
+				continue
+			KickSystem.resolve(self, col3d, fly_vel)
+			if not dead and is_instance_valid(col3d):
+				var kick_dir := col3d.global_position - global_position
+				kick_dir.y = 0.0
+				if kick_dir.length() > 0.01:
+					col3d.call("receive_kick", kick_dir.normalized(), speed_now * 0.65)
 			fly_vel *= 0.45
-			_take_damage(speed_now * HIT_SELF_DMG)
 			handled = true
 			break