A cleverly crafted racing/puzzle/rhythm game.
The audiosurf courses look like someone made F-zero courses in Tron. There are three lanes and you pick up blocks. You get points by collecting clusters of three or more in a single cluster. The bigger the cluster the more points. The colours are also worth different amoutns of points. Intense notes are red and gets you the most points while blue notes are not worth as much, but they are very numerous and you can get some insanely large clusters. However you only have a 3x7 field to place blocks on and if you fill a column without getting any clusters you lose a lot of point.
Audiosurf has more than one game mode though. For each of the three difficulties there are different characters. 3 on casual, 6 on pro and 5 on elite. The different characters have different powers that you use with left and right mouse button. However, for each difficulty there are two modes that stand out. The double vision because it is a two player mode and the mono. In mono there are only two kinds of blocks - coloured and grey. The coloured blocks gives you points and the farther you get without hitting a grey the more each block is worth (maxing at 200 per block). If you can get through the course without hitting a single grey you get a 30 percent bonus for stealth.
Possibly the game's biggest weakeness is that more and more people use Spotify rather than having music files on their computer, thus they won't get much enjoyment from the game. However, even if you don't have many files, you can get the Audiosurf with all the soundtracks from the orange box. Portal even has its own game mode with blue and orange blocks plus companion cube, which i actually quite complex and a lot of fun.
On the normal mode, most songs work pretty well as courses. High-tempo songs are extra hard, making it tough to get through without filling up your colomns and losing points, but lowtempo songs also take a lot of planning if you want to get your score as high as you can.
With mono, slower songs are really boring, but I still like mono the most, because I'm not that good at thinking quickly, so I'm better at mono which is just pure skills. And while not all the courses are good, some are amazing. I love experimenting by trying different songs and once in a while I'll find a song that is both enjoyable enough to listen to and difficult enough that I will play it for up to hours trying to get through it with stealth. So far, my five favorites are Hunters Season by Kamelot, Chapter 3 - Light world from the Super Meat Boy soundtrack, Joyride by Roxette and Sovngarde Song by Miracle of Sound. I managed to play joyride for three hours straight and finally beating it was great.
The genious of the courses being shaped by the song is that the course and music fits together like a hand in a glove. You see, when the music is fast the course goes downhill. I really love when a song is building up for an intense bridge and you see your plane approahing the top like a rollercoaster before a steep drop. Sovngarde song is a perfect example of this.
One thing that I would like to see is Mono being treated as its own mode. You see, the game lists the songs that you are the elite champion of, but getting a high score with the normal characters is way easier than with Mono. When I finally beat Joyride on Mono, I got the best time of everyone who had played that song on Mono, but just ninth place on the highscore. After all that work it would be nice to have it listed as a record. If more people had played that song with normal characters and I hadn't been on the highscore I wouldn't even have known I was the best mono player.
In conclusion, Audiosurf is a game for people who are either good at thinking fast or have lightning reflexes. With the number of courses being only limited by your digital music library and with three difficulties, plus "ironmode" anyone should be able to find a course with exactly the perfect difficulty for them. I would also really recommend this game to music geeks, because it is a cool way to analyze songs and you relly get to experiance music in a whole new way. Since I got the game during the Steam holiday sales I have so far gotten 10 hours of gameplay for every euro I spent on it and I'm quite satisfied. Everyone should at least try the free demo.