id games has released the iPhone version of Rage in two different versions, both SD and HD, available right now universally for the iPhone and the iPad. TUAW spoke with John Carmack this afternoon, and he said that the HD version is about twice as nice as the SD version: "All of the user interface is at twice the resolution, the animated characters are at twice the precision, and the world textures are at twice the feedback bias, which doesn't quite equate to twice the pixel density, but it's almost twice the data that goes in there."
The SD version will run well on both, but the HD version will stutter a bit on pre-version 4 iPhones and iPods, so anyone with a 3G or even a 3GS is advised against it. The game is US$0.99 for SD and $1.99 for HD, and as we said before, is a great-looking on-rails shooter designed to promote the full game next year.
Carmack also gave us a little hint at an as-yet undocumented feature -- he said that with the video-out adapter, gamers can play the game on a TV using the iPhone or iPad as a controller. "You can actually play the game blown up on a big screen TV," said Carmack. "It's a little bit of a mind-bender." He said that they didn't draw the controls up on the screen for the TV-out function, but it should work with the current version of the game, and may even get upgraded in the future.
That's just a little tidbit for you from the full interview -- stay tuned for a longer writeup of the game and more information about this game and other iOS thoughts from John Carmack himself on TUAW later today.