Add escape-to-pause

scenes/pause_menu.gd

@@ -0,0 +1,22 @@
+extends CanvasLayer
+
+var _enabled := false
+
+func _ready():
+	visible = false
+	EventBus.game_started.connect(_on_game_started)
+
+func _on_game_started():
+	_enabled = true
+
+func _unhandled_input(event):
+	if not _enabled:
+		return
+	if event is InputEventKey and event.pressed and not event.echo and event.keycode == KEY_ESCAPE:
+		_toggle()
+		get_viewport().set_input_as_handled()
+
+func _toggle():
+	var paused := not get_tree().paused
+	get_tree().paused = paused
+	visible = paused