GBA link up games?

[mt50]

hi, my and a mate at college have been playing link up mario kart for a few months now and are wordering what other link up games there are for the gba, right now we really only want ones that need just a single game cart to play(even if it's only a cut down link up feature)
so what link up games are there for the gba that require just one cart?
doesn't matter what type of game it is.

thanks

[Darwock]

Bubble Bobble, but I think you only get the first 20 levels with one cartridge.