Is Wii allowed as a platform or does it have to be GameCube?

The versions listed are just what platforms the games released on, not the console played. You can use whatever console you want

I'm fairly certain that Wii is allowed, I used to run Wii before mine broke and I think there are some other people that run on a Wii. If your run is Wii I think you should just submit it as GameCube.

I think the actual console you played the game on should be listed as an option while submitting, not just the platform the disc is for. For instance, if you play a PS1 game not on an actual PS1, you should be able to submit as PS2, PS3, PSTV, or whichever piece of hardware the game was played on. So I think Wii, PS3, and Xbox360 (?) should be added as console options when submitting.

As far as I'm aware, there's no difference in playing on a Wii or a Gamecube, it's really just what's convenient for you.

Thanks! Will be running this game soon in that case!

Good Luck!

Yeah, platform played > original platform