I really like the art! I like the level design a lot too. The platforming was all very fair and fun, and the falling platforms spice up the game so much. It's also really satisfying to break the walls with your shell. I would recommend creating a playable browser version of your game to make it more accessible for game jams. Since your using Unity, all you would need to do is go to file-> Build Settings, and then change the platform to Web GL. Anyways, great game!