To celebrate getting over 100,000 "likes" on their Facebook page, id Software has made Rage and Rage HD free for the week. The game is an on-rails, first person shooter and offers intense gun battles and amazing visuals. The HD version is recommended for any user above an iPhone 3GS.
Yesterday, at QuakeCon, the folks from id Software gave a little demo of Rage running on the iPhone 4. As you might expect, it's totally awesome. Not only do they achieve great Retina-resolution graphics, but the iPhone 4 pumps them out at 60 frames per second