If you care about games as an artform, you definitely need to play Rez sometime. That pleasure is now easier; Rez was just remastered and released for $10 on Xbox Live Arcade. Well worth the expense.
The conversion is good. The HD graphics look beautiful and the widescreen aspect works nicely. There's surround sound. A bit of online play in the form of leaderboards and downloadable replays. And yes, there's even trance vibrator (NSFW) support. And if you want to see how poorly we lived six years ago, you can play the original game too. Really, a perfect conversion.
To be honest Rez doesn't have the best gameplay. It's a basic rail shooter with occasional frustrating dodging and the boss fights are tedious. What makes this game so important is the pure æsthetic joy of it, the fusion of music and trippy graphics and sensory overload.
Video games have mostly become like movies, complex animations and sets and stories and intricate gameplay. Which is good when done well. Rez stripped all that cinematographic stuff away and focussed on a music and visual experience. And is deservedly well loved for that.
At the time Rez felt unique and retro, but happily now we have lots of other good options for hypnagogic gameplay: Space Giraffe, Geometry Wars, Lumines. The look of these games is unique to gamer culture, not an emulation of movies. I cherish that.