feat: add ice block variant; add button variant;

Scenes/PuzzleButton/puzzle_button.gd

@@ -2,16 +2,7 @@ extends Area2D
 var bodies_on_top = 0
 signal pressed
 signal unpressed 
-
-# Called when the node enters the scene tree for the first time.
-func _ready() -> void:
-	pass # Replace with function body.
-
-
-# Called every frame. 'delta' is the elapsed time since the previous frame.
-func _process(delta: float) -> void:
-	pass
- 
+@export var is_single_use: bool = false
 
 func _on_body_entered(body: Node2D) -> void:
 	bodies_on_top = bodies_on_top + 1
@@ -21,6 +12,8 @@ func _on_body_entered(body: Node2D) -> void:
 
 
 func _on_body_exited(body: Node2D) -> void:
+	if is_single_use:
+		return
 	bodies_on_top = bodies_on_top - 1
 	if (body.is_in_group("pushable") or body is Player) and bodies_on_top == 0:
 		$AnimatedSprite2D.play("unpressed")