Just wondering since you're choosing someone else's cartridge concept can you still retain the rights to sell the game with the same title (or even change the title) whenever the jam and voting is over?
That would be up to the designer of the cartridge. We have no ToS that assign rights. That said, we also have no hard rules on the fact you have to use someone else's cart (although it's strongly recommended). So you could also choose your own cart submission. :)