The first thing to be said about Rage HD is that it's a shooter on rails, meaning that you don't get to personally control the movement of your protagonist, who -- much like a cart on an amusement park ride -- swings to and fro under his own, mysterious volition. Given the relative lack of sophistication on offer from touchscreen controls, we feel like that was probably the sagest choice to make. It helps to make the game instantly accessible and minimizes control clutter to a degree where there's no frustrating learning curve. There is room to improve your aim and your agility in combat, but you can get by without it on the Easy mode.
Looking around is done either by navigating the screen with your finger or by tilting and turning the phone itself, whose accelerometer and gyroscope come into good use and react impressively quickly. The one niggling thing that kept irking us was that the player's automated motion also includes some camera control, so oftentimes you'll have your vision swung away from bonus items or Bullseye targets that you might have preferred to shoot before delivering some merciful death to the nearest mutants. It's clearly a part of the gameplay mechanics to make you twist and torque yourself around to achieve every objective, but it's something of an annoying one.
The few button controls are intelligently thought and laid out on screen, neither obscuring the action nor making themselves particularly difficult to find, use or understand. We also enjoyed the extra bit of sophistication thrown in to differentiate weapons -- you can interrupt reloading of your shotgun to fire off a shot, which you can't do with the assault rifle or handgun, both of which require the exchange of an entire clip. Additionally, some of the baddies can throw projectiles at you, which you're free to either dodge or shoot out of the air, depending on how much of a badass you are.
On the whole, id earns high marks from us for its control scheme (which admittedly hasn't really changed from the days of Doom Resurrection) on a game that really has no business working so well on a comparatively tiny 3.5-inch screen. That's only augmented by the professional and deeply atmospheric musical score and the, let's say it again, buttery smooth and stunningly beautiful graphical performance. If there's anything to be criticized about the look of Rage HD, it's the insipid pastel color palette -- but then we hear it's all the rage in dystopian visions of our post-apocalyptic future, so we'll let that slide.
The short single-player and non-existent multiplayer components to this game -- seriously, why not keep some proper stats and let us at least compete numerically -- limit the long-term appeal of Rage HD, but if you're looking for the best way to kill, murder, and obliterate 30 minutes of your lifetime, this $1.99 gorefest would top our list of recommendations.
N.B. -- There's also an SD version of the game available on the App Store, costing $0.99, that extends compatibility down to the iPhone 3G and iPod touch second and third generation devices.