Obviously, some leaderboards are more competitive than others. Key tracks from In Rainbows and Dark Side of the Moon are hotly contested. Less key tracks from Bob Dylan's The Bottleg Series, Vol 7 are not so. I suspect I may be the only person on the leaderboard for a recording of Arvo Part's Summa by the Estonian National Symphony Orchestra for some time to come. You'll also notice that tracks that were big in the Guitar Hero games are also big here, which is why Muse's ‘Knights of Cydonia' and Dragonforce's ‘Through the Fire and Flames' are such Audiosurf battlegrounds.
It's this sort of thing that makes me think Audiosurf must be a game, but to be honest I'm still not 100% sure. When playing it, it's actually a struggle to remind yourself that you're meant to be grabbing those blocks and not those other ones. The better the music gets and the more the whole experience gels, the less inclined I am to remember any plan or strategy I had in place before the track started. At times, it's all so damn frantic that it's hard to keep anything in mind, and you just find yourself sweeping the mouse from left to right and back again in order to gather anything you can. This isn't particularly a fault - if the aim of Audiosurf was to give you a powerful experience or just a new way to enjoy your MP3 collection, it effortlessly succeeds on both counts.
Still, it's a hard game to score. Some people will give it a go then shrug their shoulders, while others will lose their enthusiasm once the novelty of trying new tracks is over. Others still will get caught up in the clash of scores on the leaderboards, while some people out there will just get thoroughly obsessed with the whole affair. I think there's a very good chance that you'll find it fascinating for a while, and a decent chance that you'll come back periodically even once the initial rush burns out. The key thing here, I think, is the price: at around a fiver Audiosurf is cheap enough to get into even if you don't stick with it long-term. That's partly why I'm giving it an eight, but your mileage may vary - mostly depending on your love of music (or high scores) and the size and breadth of your collection. Me? I'm off to give 13 Steps another crack.
Whether you can call it a fully-fledged game or not, Audiosurf is a compulsive, habit-forming activity, and one that really does let you experience music in a new and interesting way.