poor controls
You did spend some time and effort to create good-looking graphics, level-design with small puzzles and everything. Thats good.
But the physics / controls just suck. The screen is too small, so I cannot see where I'm jumping. The character gets stuck against walls. I cannot control the height of jumps. There's an awkward pause before every jump. The character bounces. There's no concept of acceleration. Having your feet on a moving object does not cause you to move along with that object.
It really wasn't enjoyable for me because of that.