Recursion

You walked through the winter forest and uncovered a hatch covered in snow. Of course, you started to go down. But suddenly slipped and fell down. You saw the only way out, the door with the inscription "970" on it. You opened it and went inside. And suddenly the door slammed behind you. The only thing left for you to do is to go forward and not turn back. This game was made in one day by Nullxiety.