If you press 1 or 2 while in the Main Menu, it still teleports the hero. Afterwards you regain control and can walk around while super zoomed in, controls still moving the menu on the side. You can dash and jump, but cannot interact with doorways nor do torches light up.

If you fall, the kill plane doesn't work in this state. Starting a game properly enables everything and fixes the camera, but if you've already fallen you will have to restart as you cannot teleport from underwater.

That is all.