Fun.
Good, basic and enjoyable game. I did manage to find a problem.
If you try really hard, you can jump outside of the game limits.
How does one do this?
I'll tell you:
1. Get all upgrades (Stars not necessary)
2. When you jump, go right and then left after a short while so that when the line pulls you back up, you get a boost to the right.
3. Hold right, and when the line pulls you as far as it can, press space to release the line.
4. Keep holding right.
Now if you managed this correctly, you will wind up outside of the grounds limits and fall outside of the screen (and the camera limits).
This assures that the jump doesn't kill you... with an added bonus of eventually crashing flash :P