This is the new Peggle. Not that this mellifluous blend of Wipeout, Tetris and Guitar Hero is anything like PopCap's pachinko masterpiece, but rather that it fulfils the same purpose.
A bottomless tub of instant gaming snack, ideal for when you're waiting for a spot on that Team Fortress 2 server to open up, or trying to break through a hangover, or to play one-handed while enduring a phonecall with tedious relatives. Or, most commonly, just because there's a song you want to hear - but why simply hear it, when instead you can play it?
Audiosurf is one idea repeated ad infinitum, but almost entirely free from nagging repetition. That's due to the part you play in it: you are the level designer here. Pick a song, any song, so long as you've got an mp3 of it.
That's your next Audiosurf course. The track twists, slopes and undulates in time to a quick'n'dirty analysis of the song structure. You then collect or dodge beat-matched coloured blocks, forever chasing the tail of a high score - either your own or those of friends and strangers on the online leaderboards.
But that's not the real challenge. Audiosurf is a test of yourself, of the person you've become over these long years of your life. It's a test of your appreciation for music in all forms. Don't just play your favourite songs, your favourite band, your favourite genre - play the right songs.
That might be Blue Monday, it might be Bohemian Rhapsody, it might be Ghostbusters. Suppress all musical prejudice and try everything. What's important is that it's music with changes and speed-ups and speed-downs and crazed drumbreaks and bass solos and pauses and sudden explosions of noise. A song that's an adventure, a song you know will make for an incredible level.
Besting this challenge is an infinitely greater joy than topping the global scoreboard for Ace of Spades or Still Alive, or whatever else the chattering hordes are scrapping over. Within moments of embarking upon the track, you'll know if you've got it right, both from its immediate feel, how closely it seems synchronised to the underlying rhythms, and from the crazily spiking and spiralling minimap that hints at the rollercoaster to come.
Whenever you choose correctly, you'll want to beckon others over to coo at the orgasmic colours and unreal topography of your achievement.
In many ways, it's Guitar Hero without inhibitions. You're not chained to whatever noxious cockrock the publishers could afford rights to, and the overall gameiness is relaxed.
Simple mouse or cursor-key controls ease the need for extreme dexterity, but moreover there is no failure here, only self-improvement or the endless hunt for The Perfect Track. Mostly, you play Audiosurf for your own satisfaction, not to meet the game's expectations.
There's an exception to that, which is competing with a friend who seems to share your musical values. By way of example, Kieron and I have been amiably warring over the leaderboard top-spot for Kate Bush's Wuthering Heights.
Sharing a not entirely ironic appreciation for its marvellously suitable blend of shrill hilarity and melodramatic elegance, the challenge was then to prove I knew - felt - the song better than he.
To prove it with cold, hard points. Easier said than done, as we both tend towards being too caught up in the guilloche circuit, shifting in time to mad Kate's lilting vocal, the palette blossoming into rich reds (which spell, not coincidentally, mega-points) as the second chorus reaches its high-emotion peak.