The gameplay and design felt pretty solid (if a bit short!), but I had some issues with controls. The sensitivity was perhaps a bit too much? I also had some issues with seeing where I was going while holding a block.
In the third level, I had some troubles getting the crates where they were supposed to go, and there was a place where it felt like I could get stuck (specifically, accidentally dropping the crate on the wrong side of the fence).
Having more polished controls would have gone a long way in making me feel like I was more in control and thus focusing on solving the puzzles more than fighting with making the character do what I wanted them to do.