A straight up Halo-clone for the iPhone/iPod rises above its derivative nature to become the best portable FPS.
Okay let's what little bad out of the way first. You're not fooling anyone N.O.V.A. Seriously why didn't you just name the game "As close to Halo as we can get without being sued?" Practically nothing in the gameplay, visuals, character design, graphics, level design, or plot were not directly ripped off from the Halo series. Everything from the way the weapons look, to your blue holographic female support character, to the recharging shield system, to the enemy design, to the way the levels look, could of been yanked whole and breathing from the Halo games. And the two or three elements not ripped off from Halo are ripped off from Dead Space (a few interesting oxygen free levels) or any puzzle mini-game (the hacking mini-game).
So zero points for originality, but beyond that you're in for a great time. The touchscreen controls work amazingly well. The graphics are bright, crisp and smooth. The weapon loadout is standard but workable. The enemies are tough and smart.
Not being able to melee or crouch, and the lack of vehicle sections (except for a few rail shooter areas) makes the game feel a little stripped, but that's probably only noticeable because they ripped everything else off in Halo.
After a lengthy single player campaign you've also got a robust multiplayer mode which is pretty much, like the rest of the game, very Halo-esque.
I know It's kind of an odd review since mostly describing this game is basically pointing a Halo and going "Yeah pretty much that..." but it just works. It's fun to play, challenging without being frustrating, and reasonably priced.
If you own an iPhone/iPod Touch and are a fan of the FPS genre, you owe it to yourself to get this game.