I also like to add an additional challenge -- Can you use Bubble to create a program that generates solutions to the triangular-shaped golf tee game that sits on tables at Cracker Barrel? What about a program that plays chess or go?
Have to admit, I've never been to Cracker Barrel.
But for chess or go, you can certainly create a solid interface for two real players to play the game on Bubble. To build in a "computer player" would probably be difficult.
According to its site, Bubble is "a powerful general-purpose visual framework for creating web applications." Chess and Go aren't web applications.