Enter 'Space Shmup', and you get a very R-Type style track.
It's pretty cool, but I don't think it gives as varied results as the other did. "Hammer On" gives almost the same as "Space Shmup", and several other totally unrelated song names give similar tunes.
Well, the "logic" (rules, patterns, etc.) for generating the songs is exchangeable (the applet uses the file http://www.soundheli...Helix-Piano.xml by default, which is a relatively simple example).