The backgrounds are nice. It looks really cool when there's multiple layers with the buildings and the mountains.
I didn't really understand the "inversion zones"; are they just checkpoints? The guy didn't really explain them, he just acknowledged their existence, which doesn't seem super helpful?... I don't think you generally need to explain checkpoints but the game made me think that they were something more important. Ultimately it doesn't matter that much because you can catch on pretty quickly but I guess it's good to think about how to save a bit of confusion.
Also I appreciate the music :)