Bad physics.
I found the whole engine to be slightly generic. You jump on platforms, you collect big orbs, you move on. The physics were pretty horrible. When you jumped, it seemed more like you flew then you actually jumped. In one area where you had to jump on one platform underneath a cliff, and over that same cliff the other way, I didn't even need to land. The whole jump was so high I only needed to turn once in mid-air. And it all was down so slowly, I fell the same speed as I jumped. And when you walked, one foot didn't move, and the other foot was high in the air, so it looked like he was skating instead of walking. And the levels weren't designed well. To get to one part of the stage, you had to walk off screen for over five seconds. That's not too professional. And the music was pretty generic. Plus, the game had no storyline. When I'm playing a game, I want to know why I'm actually playing the game. A cat walked(/skated) around in this big world to collect orbs the same size as him. There also wasn't too much explaining. When you reached the area where you touched the blue orb to transport, I didn't know what it did because the instructions said nothing of it. At first, I though it was an enemy. However, I will say that the game had very nice graphics. Forgettable, but cute.
If you want to make a game, the best bet is to use an existing engine if you can't make one that makes a lot of sense. Remember: Obey gravity, it's the law. ;D