This is a pretty cool game, it's a shame that it crashes after the elevator level. I think a finished version of it would do pretty well on sites like Kongregate. This type of gameplay usually allows for multiple solutions, which is always a plus. You can either catapult your way across the room or carefully balance the ball to the end of the level. (Both ways worked for me in the elevator level.)

A few suggestions:

• Add some background music and sound effects for the impacts of the ball, finishing a level, etc. That would certainly improve the atmosphere.
• The trail of the ball tends to get pretty long sometimes...I think half the length would be more than sufficient. Also, maybe gradually increasing the transparency of the "afterimages"would make the ball easier to spot and be a nice effect.
• More levels!