Rhythm is a funny word. Rhythm. The more I look at it, the less I like it. Which is quite the opposite effect that Rhythm Zone has on me. Initially I wasn't all that taken with its apparently perfunctory rhythm-game presentation, but it's actually not bad, and has some cleverness under the hood. My words about this game continue below.
Rhythm Zone takes the rhythm game thing that we are also so well acquainted with via plastic instruments and brings them to the keyboard. Of course the real issue for Rhythm Zone is that it is up against a bunch of other games which are also doing the Guitar Hero thing. They're all over the place these days, and come in all sorts of flavours. There's one right here, and an even better one here. Hell, there are even some that lived and then died again, like InstantJam, which went down with the demise of garage games.
I would have been unable to continue being interested in the game if Rhythm Zone hadn't basically been the complete package, with a bunch of its own music, but, more importantly, a system for allowing you to add your own tracks to the game. This process does magic on the track and creates a level out of it, and will also allow you to select different difficulty levels to try. This is pretty neat, even if its browse functionality is a bit crappy and you need to store your music on your C: drive to find it. Just a few seconds wait (.wma and .mp3 files were what I converted) and I was playing levels based on the random nonsense that lurks on my computer, from Mozart to Lightning Bolt, and - the big surprise - the levels the game creates are actually pretty well mapped to the tune. The game lights up with psychedelic backgrounds and the tune-made-coloured sequences makes sense under your fingers. Like the best of the rhythm game genre, it's impressive stuff.
Of course the processing of tunes is done elsewhere too, because there's also Audiosurf. Not quite in the same game, but certainly close by in the neighbourhood, and what it does is both better looking and a little more PC-friendly than the classic rhythm game technique. Well anyway, the best way to judge is probably to play the demo, which is just here. Go take a look.