If i understand well, pressing space will change the reality you are.
There are 5 realitys:
- Normal: There are trees in the way
- Snowing: Best reality, not in your way and nothing chasing you.
- Black wall: There is a wall behind you preventing you from coming back
- Dark world: A creature will folowing you
- Hollow world: There is something following you with a bell, after some time you dies
Each time you change reality, the longer it takes for you to be able to switch again.