The game concept is really interesting. I think that with a litlle more polish, this can become a great game! The music is a bit repetitive, and you could definetely add more instruments to it to make it a bit more interesting and less tiring! The SFX are great, though. Good job on that!
The level design is a little bland, but it is hard to think of some way to explore this mechanic to its fullest, so I understand. I'm glad that the collisions were well handled, so I didn't clip on the walls every time I switch sides!
The visuals are basic, so they do their job. I think the menus deserve some work, though, as they don't fit that much with the game.
Overall, I see great potential with this game. If you continue work on this project, I'd be glad to play the final version! Excelent job!
I'd be glad if you could try out my game, too!