Though a bit sloppy on technical aspects and a bit short, Colosseum is a perfect side-trip of a Pokemon RPG.
Pokemon Colosseum is set in the region of Orre, and starts with the hero (whom you control) stealing a Snag Machine from a base of the team he betrays and quits. That's right, you control a former villain. You start with an Umbreon and an Espeon as your "starter" Pokemon, and they're already quite strong. The hero then goes on a quest to defeat the gang he recently betrayed. After saving a girl with the special power to see "Shadow Pokemon", the Pokemon you can catch in the game, the stage is set and the journey lies ahead.
In this game, all battles are Double Battles and they're always against other trainers. That said, there's plenty of trainers to fight and many of them will fight you again and again should you choose to speak with them. Some trainers will have "Shadow Pokemon", Pokemon corrupted and had their hearts closed by the villainous team Cipher, whose plan is to take over the Orre region using these cold-hearted Pokemon. Your partner will alert you if someone has a Shadow Pokemon, and catching it works like it does in all other Pokemon games. Whittle its health down, throw a Poke Ball. Only Shadow Pokemon can be caught. Nothing else. Sadly that limits your choices, since there aren't too many Shadow Pokemon in the game. However, you are given enough to work with.
To use a Shadow Pokemon efficiently you have to first purify it. While this process sounds easy, and it is for the most part, it often takes longer than the player would want and it can get frustrating if some circumstances continue to pop up, such as a Pokemon repeatedly entering Hyper Mode, which causes it to skip that turn in the battle, or if the Pokemon just flat-out takes a very long time to get its "Heart Gauge" down so you can purify it. After purification the Pokemon is free to be trained just like any other Pokemon, and no longer has the restrictions that came with it as a Shadow Pokemon.
The graphics aren't that well done in this game. While that live up to GameCube quality, they're not very smooth and overall look fairly sloppy. They do, however, get the job done, and they are by no means "bad". The Pokemon models look decent and the character models look alright, but the best visuals is some of the areas visited in the game, like Pyrite Town, which looks fittingly slummish as the town filled with ruffians and troublemakers.
The camera sadly is the biggest technical issue I could find in the game. Though it moves with the player during overworld segments, it sometimes hides certain things like item boxes as it doesn't change its angling for the most part. In battle, the camera has a tendency to zoom too close to the Pokemon, often cutting off the part of the Pokemon that should be focused on (the head/face), and many times they may be off-centered.
The music is a treat. It's quite catchy and it does a good job of helping the feel of the game be what it should be at a given moment. If a point in the game should feel more "epic", more "epic", orchestrated music is played. The battle music and overworld music are both great together and overall are a good part of the experience of the game.
Pokemon Colosseum also has a multiplayer mode which can both be played as a "Quick Battle" version or a Game Boy Advance hookup. Either way, the multiplayer is a decent quick fix if you and a friend don't have the Pokemon to go at it but want to do so anyway. However, almost all the enjoyment one should get from Colosseum should be in the single-player mode.
While it's a bit sloppy and could've used more variety, Pokemon Colosseum manages to prove Pokemon can do a story, and it can be more than just traveling a region, collecting monsters, and challenging some league to be the best. It can be more than that, and Colosseum is a good example of that potential.
Final Score: 7.4