Great idea! I think it's safe to say it could use more polished art, but eh, it's a game jam, so it still works. The biggest bang for your buck art wise would be a custom skybox, and a few lighting tweaks to compliment the solid colored materials.
Controls wise, the mouse was a little sensitive and jumping was kinda awkward. That said, I like the camera angle, and other that what was previously mentioned, movement felt good. I also liked the idea and can see a lot of potentials puzzles!
Not sure how you feel about the game, but it could be really fun if you continue working on it!