Official story and features:
"In this innovative game, players can upload Pokemon from their Game Boy Advance games Pokemon Ruby and Pokemon Sapphire, and battle against friends on their televisions through Nintendo GameCube.
With a collection of arenas to choose from, players can enter their Pokemon in a tournament or battle it out in four-player multi-battles, making each experience unlike the last. Players also can join with a friend to combine strengths in new two-on-two battles and demonstrate their Pokemon prowess as a team."
Story from Nintendo site
"- A follow-up to the highly popular Pokemon Stadium and Pokemon Stadium 2 games for Nintendo 64, Pokemon Colosseum continues the fun and excitement in collecting a whole new batch of Pokemon characters.
- Completely compatible with Pokemon Ruby and Pokemon Sapphire, players can battle with more than 200 Pokémon from the two games on their Nintendo GameCube. Players simply insert their Pokemon Ruby or Pokemon Sapphire game into the Game Boy Advance, connect to a Nintendo GameCube via the Nintendo GameCube Game Boy Advance cable, and Pokemon appear in Pokémon Colosseum!
- Up to four players, each with a Game Boy Advance system, can connect to Nintendo GameCube and battle their Pokemon against each other. Pokemon Masters must overpower the competition in various tournaments to become the best Pokemon trainer ever."
Features from Nintendo site
It's brillant I can't stop going on it. I tell you it looks so life-like as if you're playing in the game!
-- From lets just say the poke gal
This game for me is the best Pokemon game created at the moment. The graphics and the story are the best of these Pokemon games.
-- From rafael
Pretty neat graphics, if only you could buy items for yourself.
-- From Jason
I think this game is 100% cool and so does my 10 year old brother Evan.
-- From Ian Kai Krause