When asses need to be kicked, Lex is the man for the job.
Keys:
arrows to move around, up to jump
space bar to shoot
m to mute the horrible music

I should have added sound, but I ran out of motivation.

update:
1) now with a windows build :) (Arrg, the readme is missing. My internet is way too slow for me to waste another half an hour re uploading the archive though.)
2) I fixed a potentially fatal bug, if you downloaded before the post was updated you may want to update
3)previously undocumented keys:
spacebar to start the game from the title
esc to skip the intro, return to title from game and quit from title