Audiosurf

An indie videogame developed almost solely by Dylan Fitterer and available for purchase on Valve's Steam service for a low-low price.

Throw F-Zero into a Klax track and make it a music game (though not a Rhythm Game in terms of timing button presses) in much the same vein as FreQuency and Amplitude (By Harmonix of Guitar Hero and Rock Band fame), gauge performance by implementing an online scoreboard for every single song played, and design the game so that it can take almost any audio track in most common formats and generate a playable track out of it. Y'know, the sort of game that is probably a controlled substance in several countries. The genre is hard to pin down, but can broadly be described as a Puzzle Game or Rhythm Game.

The gameplay is deceptively simple. The game has you riding a small spaceship down a colorful, bumpy track (its shape generated based on the music file you provide the game with) with colored blocks scattered throughout, which you use to score points. There are two major game modes: Mono and Puzzle, the latter being divided into several "characters" or playing styles (Pointman, Pusher, Vegas, Eraser, and Double-Vision.) Both require you to match up three same-colored blocks, but in Mono there is only one type of color block, and gray blocks you have to avoid. The Puzzle modes have three to five colors depending on difficulty level, along with an array of powerups. The objective is to make as many and as large matches as possible (and if you're on Mono, do it without hitting any greys) to get a high score.

The ability to play any song is the game's unique selling point. Rather than being restricted to whatever tracks and artists the developers could buy, you can just go with anything in your CD collection. If your music collection sucks, then there's also the in-game "radio" system where the developer selects a bunch of indie tracks suggested to or discovered by him; plus the fact that the game comes with the Orange Box soundtrack bundled with it for free. Yes, that includes Still Alive.

Some people at the GameFAQs community have tried figuring out a plot to this game. This topic comes closest to what the plot actually is. Then again, with an acid game like this, who needs plot?

A game known as "Audiosurf Air" is apparently in the works. It is unknown at this time exactly what it is, but there are some screenshots and a beta signup available on the website.

YouTube won't stop until every single song in the world is ridden.

See also Beat Hazard.

Tropes surfed over by this game include:

 * Alternate Reality Game: Is one of the Potato Sack: 13 indie games that form the bulk of the material of Valve's "PotatoFoolsDay" Portal 2 ARG.
 * Better Than It Sounds: It really is.
 * Character Select Forcing:
 * If you want the Pro throne on a popular song, and it's a slower one, using any character other than Vegas will probably be futile. Prior to the update that buffed Vegas and Eraser, it was Pointman dominating the scoreboards.
 * And if you want the Elite throne on any popular song, it's nearly impossible to do so if you use Ninja Mono.
 * Difficulty Spike:
 * Any Elite character on Ironmode. On some songs (*coughthroughthefireandflamescough*), any character on Ironmode, period.
 * Happens a lot in-song too- Radioactive by Kings of Leon goes insane when there is a chorus.
 * Disney Acid Sequence: Edit the screen colours and select the screen filter to create your own special acid trip!
 * Double Play: Double Vision gives you two cars to control, either yourself or with a second player.
 * Everything Dances: The background objects dances to the music, whatever they are. Even the road you're surfing on bounces and bumps to the beat!
 * Falling Blocks: It's not game over if you let a column fill up (unless you're on Ironmode,) but it will set you back.
 * Hostile Show Takeover: Combined with Crossover and Breaking the Fourth Wall. During the Potato Fools Day ARG, G La DOS from Portal invaded the game and forced players to play The Device Has Been Modified (in first person, holding a Portal Gun, no less). Getting Gold on the level unlocks a clue to solving the ARG's puzzle.
 * Idiosyncratic Difficulty Levels: Casual, Pro, and Elite; the Elite version of Mono is "Ninja Mono." Some characters are restricted by level: Eraser and Pusher aren't available on Casual, and Vegas is Pro only. Ironmode is not a separate difficulty level, but a modifier that can be applied to any playstyle and level.
 * Let's Play:
 * Step One: Go to YouTube.
 * Step Two: Search for "Audiosurf".
 * Step Three: Spend a weekend watching runs.
 * Luck Based Mission:
 * Vegas's special abilities are entirely luck-based, and no matter which character you play, powerups and white blocks won't be in the same places every time.
 * Due to the prevalence and random positioning of the Paint and Multiplier powerups, any Puzzle character on Casual or Pro levels can fit this trope, at least when good players are jockeying for the top spot on the scoreboards.
 * Marathon Level: Literally any long piece of music will make one. A song greater than 12 minutes can go for 300k-400k on average run in Ninja Mono. If's it's upbeat, expect higher.
 * There is an achievement for successfully avoiding all gray blocks in a Marathon Level on Ninja Mono.
 * Match Three Game
 * Meta Multiplayer: Of the Leaderboards variety.
 * Music Player Game: Trope Codifier.
 * Overly Long Gag: This run of John Cage's 4'33".
 * Portmantitle
 * Scoring Points: It's one of the few modern games wherein a high score is the main goal.
 * Shout Out: You get an achievement for making a match of exactly 24 blocks. This achievement is called "Bauer".
 * Tron Lines: Seen on the cars and parts of the scenery.
 * What Do You Mean Its Not Awesome: Make any audio file into something playable into this game. ANYTHING.