This was a pretty nice game! I was surprised at how many levels and ideas you got from this simple mechanic. Also, the difficulty curve of the puzzles was well done. I never felt frustrated, but I still had to think for a bit on how to solve them . I really liked the final puzzle, when you have to throw a square and jump at the same time; all of the necessary pieces of knowledge were already learned in the previous levels one by one.
I also have to say, its pretty impressive doing a game without an engine :0
Awesome work!!