Viewtiful Joe, is hands down, one of the best games ever made.
Viewtiful Joe starts off with, quite frankly, a story so bad, you want to play the game to see what it's gonna do next, you can forgive the awful story though because the game isn't story driven. Average Joe and his girl, Sylvia, are watching an old movie in theatres, starring Joe's hero, 'Captain Blue'. Captain Blue loses a fight, the villan reaches out and takes Sylvia into the movie, Joe, is taken into the movie by 'the' vehicle. Under Captain Blue's guidance, Joe is about to replace Captain Blue as the superhero. Lame I know, but it gets better.
Viewtiful Joe is a cross between 2D and 3D. The game itself runs in 2D, with 3D environments/background. The cell-shaded, 2D/3D graphics are absolutely stunning, and it runs very smoothly with no sign of slowdown. Joe has 3 special tactics he can use to his advantage, Slow-Mo, which is pretty self explainitary. Mach Speed, in which the game goes at a much faster rate (yes you can run faster too), and Zoom In, which the camera zooms in on Joe, and he can perform ultra attacks on enemies. Also, during slow-mo, Joe can dodge bullets, and various other attacks, but it will cost you most if not all of your VFX meter, which allows you to use these 3 tactics at your disposal. If you run out you become regular Joe for a while until your VFX meter reaches a certain point.
Joe can also learn new attacks, in a very similar way that Dante from Devil May Cry learns new attacks. You earn V-Points in the game, you earn more on how you play your game, a massive combo attack will score you mad V-Points (yes it's possible to get 9999 v-points in one combo). After each level, or 'Episode' you goto a screen in which you can buy lives, new attacks, or life gauge meters, or even bombs/Voomerangs Joe can use.
The game takes place in various movies, which are based off of real movies, I'm not a movie buff, so I couldn't tell you which ones in particular except that I think the last episode is a Star Wars-esque level. The levels are very nice, and are also sleek in design. The game has nice techo music, and some seriously good, yet corney voice overs, but much like the story, you forgive it, in this case because the actors are good, just some of Joe's one liners are really bad. But hey, he's a superhero, and not all of Batman's one-liners were jems either.
This is the best Gamecube game currently available, and for $20 bones you'd be cheating youself out of an experience like Viewtiful Joe. Do yourself a favor and go buy this.