DS: This system covers every one of your favorite games. It's cheap, it's got good battery life, it covers a great variety of genres (except Shooter), and has the vast majority of announced current and future 3rd party support. Get this.
Metroid Prime DS is a good FPS (Yeah, I know, adventure. This game is clearly a FPS though if you play it) and I have heard that Brothers in Arms DS is a good game as well. So between those two games its not really terrible for shooters. Its a shame it doesnt have more though, its control system is really quite good for them.








