Here, I have texture mods, tweaks, and a video-making tutorial.
See also my script for surfing the current song from foobar2000.
Audiosurf now has customizable textures.
Here are some textures that I've made, specifically for Mono characters. They can be used for other characters, as long as you copy and name files correctly.
I went for a generic, classic look.
Note: these images are stretched here to appear visually correct.
There are other associated mods earlier on in the audiosurf textures thread.
The Audiosurf user experience (as of the time of this writing) isn't exactly polished yet. We hope they continue to improve upon it.
Here are a few other things you can do in the meantime. However, this will affect all users of Audiosurf, since it deals with modifying files directly—not a problem if you're the only one playing.
If you want to move the Orange Box OST elsewhere, or delete it, steam will redownload it whenever Audiosurf needs an update (or reinstallation). This is a waste of time & bandwidth.
The Orange Box Soundtrack folder is located in \steam\steamapps\common\audiosurf\engine\ . After moving the Orange Box Soundtrack folder elsewhere (or deleting it if you don't want it), you can replace it with my set of blank files.
If you don't want to use Chimes, then you can swap folder names with Chimes. The sound effects folders are located in \steam\steamapps\common\audiosurf\engine\soundeffects\ .