This is a really good concept, and I like the application too.
Switching between dimensions is made pretty intuitively and the aesthetic makes a good use of the limitation. I do wish the controlling part was a bit smoother tho, game requires a lot of tight turns, which is a bit annoying(thank god for checkpoints), and going uphill just by horizontal force is a bit slow and made me wonder if it was really the way to go... which I'm still not sure, I could be just playing it wrong.
Additionally, dimensions having different backgrounds is really cool looking, but it made me kinda wish it also had few differences in level design, rather then just physics.
overall, pretty lovely!