Nice little game!
My main problem with the game is the controls, it feels like you move to fast and the fact that when your just moving around it looks like your jumping but your not actually jumping is very weird and kind of confusing.
Another thing is I love the main mechanic were you switch realities but I think you could have used it more (maybe you did in the later levels I could not make there because of the controls). The mechanic may have worked better if it had some more puzzle-ish uses, rather than press a button and you can now finish the level
Lastly and least importantly the art could have been better with just a tiny bit of work. Maybe switch out the skybox, add some fog, and post processing effects!
Overall I think its a good game I like the main mechanic and idea I just wish it was used more!
P.S. last thing I forgot when writing this is that I love the music but I would of liked some more sound effects when jumping, running, etc.