We fired up the PS3 version, and the first thing we noticed was how crisp it looked. Our demo largely showed off Necropolis, a stage that shows off the Necris' native environment. We'd describe the art design as something along the lines of if H.R. Giger got to design Constantinople.
Control-wise, UT III will let you play with a controller or use a keyboard and mouse setup. We played with a Sixaxis, and noticed that the action felt pretty smooth for a console FPS. Primary and secondary fires both felt intuitively placed on the shoulder buttons, and both reloads and jumps worked well.
In the single-player portion of Unreal Tournament III, you'll have a branching campaign written by the author of Gears of War's storyline. The path you choose at certain pivotal points will, as it has with multitudes of other games, influence your ultimate outcome.
The logistics on downloadable mods are still being worked out, but if all else fails, you'll be able to get a mod from the PC version, slap it on any portable memory device that the PS3 can read, from USB drives to Memory Stick to SD Card, and put it on the PS3 hard drive. You'll also be able to install portions of the game to the PS3 hard drive to shave off some of the loading times.
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Video demonstration of PS3 version @ GameTrailers