Actually Kid Chaos has about 160 colors for backgrounds, etc. and not just copper gradients. Pretty clever use of a 2bit playfield (yes 2, not a typo

. There's a few interviews with the author around the net where its spoken about.
As for the fixation with rave/techno type music, Id hazzard a guess it stems from the fact that its easy to write and requires no real talent. It can also be written with small samples so has a small memory footprint.
(sorry, being that Ive been an actual musician for over 20 years I have a particular dislike of that sort of garbage
