One of the best shoot'em up games of all time
What I loved about this game is the fact your ship can change colours (makes your ship immune to same colour projectiles) but not immune to the other colour. In the gamecube version (not sure about the other versions) you can have the game either horizontal or vertical. I prefer it horizontal, because it fits widescreen TV's better, but it was meant to be played vertically, so the purists say.
Lot's of fun, great graphics, great controls, playability and very addictive. It's a game that will stand the test of time. Bad point about this game: difficulty. This isn't intended for 6 year olds to play.
My rating for this game is an easy 9 out of 10. I recommend buying it, but prices are usually high for this game. If you can buy it for less than 30$, buy it without hesitation, since you can easily sell it for the same amount if you don't like it. A collector's must have and play.