I created a countdown timer
onready var gametimer = getnode("Score Counter/UI/Base/game_timer")
func process(delta):
timelabel.settext(str(int(gametimer.gettimeleft())))
func ongametimertimeout():
gettree().changescene("res://scenes/game_over.tscn")
func ontimebodyentered(body):
if "player" in body.name:
$game _ timer.waittime += 10
queuefree()