I love this game and alls its prequels. The only thing I would change in this one is to let people play around with the factory with all tools available in order to make some really awesome balls. People shoulder be able to submit those they create in there instead of the drawing at the end thing.
I would suggest making a message to let people know that there is a mouse sensitivity option. I went from 0-900 and then had to double the sensitivity because there were turns I literally could not make. Awesome job with the game and superb developer feedback!
 "Monsters & Dungeons"){kind=icon}
 "Factory Balls 4"){kind=icon}
 "Accelerator"){kind=icon}
 "Red"){kind=icon}
Love the idea of a message that tells people about the sensitivity option, good thinking batman :)