Audiosurf is a rhythm game where you ride a spaceship across a road collecting colored blocks. Unlike other music games, the music here is actually music files on your PC, meaning every single song in existence is an Audiosurf song, even songs that came out after the game's release.
That's a lot of songs.
Present in the laddermusic folder of the game's directory.
A 44-second flute song, possibly made for testing the track generator.
A Portal remix called "The Device Has Been Modified", credited under "Victims of Science". The song itself in-game appropriately uses the [as-portal] tag. Present in the comments section of the file's properties is a developer message:
Thanks for Portal Valve, you are awesome. Wow I didn't know this would have such a warm reception. I went back and put the effort into it that I should have the first time.
The song was included in an August 12, 2011 update as part of a Valve promotional ARG. When the player booted up the game, the first song they chose would be replaced by this one instead. This was disabled in a later update, though the song stuck around in the files afterward.
Each of the four sound effect themes contain three sound effects that go unused in the final game. "matchformedOLD.wav" is a unique sound effect, likely from before different sound effects were added for different sized block matches. "overfill_safehitOLD.wav" is the Windows Ta-Da! sound effect; it's unknown where this would have gone. "tilefallOLD.wav" is a Windows "ping" sound effect that is used in the game, but in a duplicate file.
An outtake of a line from one of the tutorials can be found at "rush down.mp3".
Unused Game Modes
Options.ini contains an option for a touchscreen mode that's normally set to 0; changing it to 1 will do nothing to the game.
QuickPicks.cgr contains a list of file names for songs likely used for testing. These are stored before the player's recent songs.
04 - Map Of The Problematique.mp3 04 10,000 Days (Wings, Pt. 2).wma 04 10,000 Days (Wings, Pt. 2).wma Little Spitfire - Silly Girl.mp3 Little Spitfire - Say Hello.mp3 Little Spitfire - If I Look I See You.mp3 Little Spitfire - Drama Queen.mp3 Jason Sean - Ocean of Memories.mp3 Jason Sean - Infinite Journey.mp3 Jason Sean - Aurelia's Return.mp3 07 Just Like You Imagined.mp3 09 Pilgrimage.mp3 10 No, You Don't.mp3 NowThatsSacred.mp3 TheseDays.mp3 The Giant.mp3 NowThatsSacred.mp3 Yeah Yeah Yeah.mp3 HollywoodEndings.mp3 Eat.mp3 Zetan Spore - Stratosphere.mp3 Zetan Spore - Burn Up.mp3 10 - The Come Down.mp3 HL1_song13.mp3 HL1_song10.mp3 10. January2.mp3 08. Catch Them All2.mp3 06. Some Racing, Some Stopping2.mp3 02. Cherry Tulips2.mp3 01. Get Yer Head Around It2.mp3