i finally found the manual, and for Sonic Advance on GBA, you do only need one cartridge to do a two player time battle.
However there's a difference between a 2d side scroller and a 3d Blue Rose engine. Sonic Advance was little more than a port of a sega genesis game, it might require all players to have cartridges to do a link with WCP.
BTW, I was thinking about space for a few seconds. How much of the original prophecy game was FMV and how much was the actual game on the 3 CD set(or was it 2 CD?, I don't know I never bought the original, only gold).
However there's a difference between a 2d side scroller and a 3d Blue Rose engine. Sonic Advance was little more than a port of a sega genesis game, it might require all players to have cartridges to do a link with WCP.
BTW, I was thinking about space for a few seconds. How much of the original prophecy game was FMV and how much was the actual game on the 3 CD set(or was it 2 CD?, I don't know I never bought the original, only gold).
At the very least, even if single pak multiplay is supported, you'd probably get more features if everyone had a cartridge. For example, if both single and multi pak options were available, in single pak mode everyone would probably have to use the same fighter or something like that.