Holycrapit'shere. The splattertastic shooter Rage HD from Id Software—you know, the Doom and Quake guys. The graphics are unbelievably good, the best of any iPhone game yet. It's a must-download if you love shooters—just look. It's nuts.

It's interesting that id's decided the best way to do a first-person shooter on the iPhone is as a rail shooter, almost like a throwback to old-school arcade shooters (for some reason, the quarter-devouring, Aerosmith-starring Revolution X and the T2 game come to mind). You don't move, you just point and shoot. And it's great. Mutant blood splatters everywhere. There's bonuses to be shot at as you move through the level, if your reflexes and aim are quick enough. The tilt controls feel tight enough on the iPhone, actually preferable to the faux d-pad on the iPad. (Check out what John Carmack has to say about it.)

All in all, it's surprisingly solid to play, combined with truly amazing-for-a-phone graphics. While it maintains the pick-up-and-playability iPhone games need to have, hopefully it's part of a coming onslaught of more serious iPhone games for serious gamers. Remarkably, it's only $2, and it's a universal app iPhone and iPad, so it's a genuine deal. Fair warning: It's a whopping 746MB. But it's easily the best $2 and gig of storage you'll eat up all day. [iTunes]