Hi!
In order to make it easier for people to find all modified .ash-songs that I made, here is a list. I will update it in the future as I make more of them.
Remember, to use the modified tracks, move the .ash file to your "Steam\steamapps\common\audiosurf\engine\audiosurfHC" folder.
Superdifficult challengesEurofighter - the "classic" superdifficult challenge. It's fun not only with Mono, but also with Pusher, and even Pointman and DVE.
http://www.audio-surf.com/forum/index.php/topic,4153.0.htmlBallade of blocks - used to be superdifficult, but since the color flashes have been removed, it's basically very similar to Eurofighter (however, if you still have an old version of Audiosurf somewhere, play it on this old version and the color flashes will work properly!) Also, the top score of 522k appears to be cheated, since due to the [as-monopt1] tag the few colored blocks in the track are not sufficient to get this score...
http://www.audio-surf.com/forum/index.php/topic,4146.0.htmlInvasion of the reds - this one is a bit different, and mostly aimed at DVE. Apparently you can also use other input devices than the keyboard for the left ship, which was not really intended by me
http://www.audio-surf.com/forum/index.php/topic,5198.0.htmlAn Alien song - if you prefer "regular" tracks, this song is for you, as this is the most difficult challenge so far without speed bursts or color flashes. Unfortunately many people failed to use the modified .ash-file on this song (which can seen by some subtle differences of the track shape), so the score board is quite polluted.
http://www.audio-surf.com/forum/index.php/topic,4865.0.htmlFinal Audacity - Basically this is an even more difficult version of "An Alien Song", with a song which sounds like a Trance version of the song of "The Ballade of blocks". Also, due to some precautions the scoreboard should be significantly less polluted by people who fail to use the modified .ash-file, and it should be much easier to identify them.
http://www.audio-surf.com/forum/index.php/topic,5432.0.htmlMixes:Trance seven - 7 trance songs of increasing difficulty mixed into one big track, with modified ashes to make the last songs really difficult
http://www.audio-surf.com/forum/index.php/topic,4134.0.htmlTrance Trance revolution - Similar to Trance seven, except that it starts out fast, but doesn't become too hard in the end. Also, the music is even more intense and faster
http://www.audio-surf.com/forum/index.php/topic,5224.0.html