Nothing else is like it - and more things should be like it.
Rez didn't quite reach the immersion factor I sought. But wow, is it an amazing experience. This truly is an all consuming game. It's downright amazing what the Dreamcast can pump out - sure, it's only thirty frames per second, but in 480p, this game looks amazing, sounds amazing, and is overall just an incredible experience. Tetsuya Mizuguchi and company are going to take you on a ride - and they've all ready taken a heavy dosage of LSD (but you can join in on that part if you'd like).
The music is phenomenal. I bursted out laughing the first time I realized what they were saying on the final level. (Frank Herbert fans will be amused.) The story is suitably minimalist, always staying in the background. It only comes to the forefront in the final level, and those fifteen minutes of gaming alone are worth finding a copy of Rez for. You may not know all the specifics of whatever story UGA made up - but it doesn't matter. Playing through level 5, you get the impression you're both witnessing and playing something deeply meaningful - it's such a soothing and excellent sensation. (Religion is the opiate of the masses, after all, Carl Marx. Though Rez is no religion, there are certainly some very religious overtones.)
Yes, Rez is linear. But every moment is calculated, every tone used to great effect, every flashing light there to mesmerize you, turning the entire game into a beautiful set of flashing lights, enjoyable sounds, and, if you have a rumble pack, a (very) tactile experience.
I've recently begun to turn to old school 2D shooters for my fix, for my attempt at immersion, for that zen like state of total awareness (which is why I've gotten my hands on a Dreamcast), but Rez is truly a joy to play. If you find its visual style appealing at all, if you like electronica at all, if you liked any old school rail shooters like Space Harrier or Panzer Dragoon, and you have yet to play Rez - do yourself a favor and play it. It doesn't matter if it's on the Xbox 360, the PS2, or this - just play it. It's truly worth your time. UGA made a game that stands up to the test of time - and until more people start making strangely meaningful interactive metaphysical journeys, it will continue to stand up to the test of time, devoid of competition.