surprise_dungeon/objects/oGame/Step_0.gml

// chrono
if (!perdu) {
	global.secondes -= 1/room_speed;

	if (global.secondes <= 0) {
		global.minutes --;
		global.secondes = 20;
	}

	if (global.minutes <= 0) {
		perdu = true;
	}	
}