game: add xp orbs

scenes/enemies/enemy.gd

@@ -15,6 +15,7 @@ var max_health: float
 var god_mode: bool = false
 var is_dead: bool = false
 
+var _xp_orb = preload("res://scenes/xp_orb.tscn")
 
 func _ready() -> void:
 	move_speed = default_move_speed
@@ -57,11 +58,17 @@ func die():
 	if is_dead:
 		return
 	is_dead = true
+	drop_xp_orb()
 	target = null
 	velocity = Vector2.ZERO
 	animation_player.play("die")
 	animation_player.animation_finished.connect(_on_die_anim_finished)
 
+func drop_xp_orb() -> void:
+	var orb: XPOrb = _xp_orb.instantiate()
+	orb.value = 5
+	orb.position = position
+	get_parent().add_child(orb)
 
 func cheer_anim():
 	if not animation_player.is_playing():