Believe it or not, there are some good FPS games for the iPhone – most are bad, but there are some good ones. Games like N.O.V.A. and Modern Combat Sandstorm are playable and enjoyable on the little screen, and the controls aren’t too bad either.
Electronic Arts/Visceral Games released a great video of the gameplay for the iPhone version of Dead Space 2. It looks completely playable – not the quality you’d find on the 360 or PS3 version, but it looks promising.