Definitely a challenging game but I loved the idea of an endless running with flip mechanics. The audio and switching effect when you flipped between worlds was awesome! There were a few bugs/issues that I found while playing:
- If you go left at the very start, the camera just floats off to the left side indefinitely.
- As others have mentioned, when phasing, the pause feels too long.
- I also found phasing quite difficult to use, most of the time I just ended up falling through the floor and dying.
- It was possible to get stuck in walls when flipping between worlds, but I guess this might be intentional :D
- There was a bug in the tutorial where the menu doesn't hide, but I see you addressed this already in another comment.
I think this could actually be a really great game with a little polish, I hope you'll continue working on it!