Good job. I could see this being expanded into a full length game, though it would need more interesting environments to throw blocks around in. I did notice a few issues though. It wasn't obvious initially that I was supposed to shoot the green blocks. Also I noticed a few of the walls weren't aligned with the floor. Other than that I think the climbing into the sky constantly isn't ideal because it means it's all the more frustrating when the player falls, and because it gets samey after a while.