Reasonable Progress
My game is already half-playable here: http://www.inf.ufrgs.br/~rcpinto/LD24/
It’s still not possible to die and there is no hud, powerups or different weapons, which I plan to add tomorrow. But it’s already possible to kill the enemies and see their behavior evolve! To achieve this, I’ve used a simplified genetic algorithm combined with a single layer neural network.

And since I didn’t post my setup before the competition start due to some strange word press bug, here it goes:
Language: HTML5/JS
Engines/Libs: Crafty + Sylvester
Editor: Gedit
Audio: Bfxr + Audacity + Wolfram Tones + Timidity
Graphics: Gimp + Inkscape
Tags: Crafty, evolution, Genetic Algorithms, html5, javascript, ld24, Neural Networks