Wow, one of the best games I've played so far. Assets and code from scratch? Awesome work! The puzzles were really challenging and made a lot of fun.
I enjoyed the background music, the only thing which was a bit exaggerated was the sound of the jump (a bit to intensive/too loud?). If you use a such intense jump sound I would change the pitch dependent of a random value between two constants, so it sounds every time different and is not that outstanding.
Love the look of the game. Good job!