In my opinion, the following are all viable choices (with the possible exception of Freezeflame and Wart's throne room):
- Super Mario Bros. 2 ~ Wart's Throne Room
- Super Mario Bros. 3 ~ Grass Land
- Super Mario Bros. 3 ~ Airship Level
- Super Mario Galaxy ~ Comet Observatory
- Super Mario Galaxy ~ Freezeflame Galaxy
- Luigi's Mansion ~ Rooftop
- Mario Party ~ Mario Party
- Mario Kart Wii ~ Coconut Mall
- Donkey Kong country ~ DK's Tree House
- Donkey Kong Country ~ Gangplank Galleon
- Mario VS Donkey Kong DS ~ Mini Mario Stage
I'd have to say SMB3 Grass Land, Airship, Comet Observatory, Luigi's Mansion Rooftop, Mario Party and/or Coconut Mall, Gangplany Galleon, and the Mini Mario stage would be my choices. Or perhaps in place of the Comet Observatory, there could be a stage designed similarly to Delfino Plaza that transports the fighters to different galaxies. I think one more classic Mario stage could potentially added as well, but 5 or 6 (not including the DK stages) is probably enough.
- Super Mario Bros. 2 ~ Wart's Throne Room
- Super Mario Bros. 3 ~ Grass Land
- Super Mario Bros. 3 ~ Airship Level
- Super Mario Galaxy ~ Comet Observatory
- Super Mario Galaxy ~ Freezeflame Galaxy
- Luigi's Mansion ~ Rooftop
- Mario Party ~ Mario Party
- Mario Kart Wii ~ Coconut Mall
- Donkey Kong country ~ DK's Tree House
- Donkey Kong Country ~ Gangplank Galleon
- Mario VS Donkey Kong DS ~ Mini Mario Stage
I'd have to say SMB3 Grass Land, Airship, Comet Observatory, Luigi's Mansion Rooftop, Mario Party and/or Coconut Mall, Gangplany Galleon, and the Mini Mario stage would be my choices. Or perhaps in place of the Comet Observatory, there could be a stage designed similarly to Delfino Plaza that transports the fighters to different galaxies. I think one more classic Mario stage could potentially added as well, but 5 or 6 (not including the DK stages) is probably enough.