Hey not bad. It got a little frustrating near the end, especially having to collect those keys; but the graphics were cute and the game-play was simple and easy to understand. Good job.
If I could make one suggestion though. The green portal looks like acid or something, and in the beginning I thought I had to avoid it. Maybe making it a more obvious color (like yellow or aqua), or changing the design to an arrow, would have been more effective :)