Back2Hack 2002 entry

This was my '''Back2Hack 2002''' entry. In the Back2Hack competition, you had to write a game, using an emulator of the (fictive) BackMobile hardware to access video/sound/input/timer - and the BackMobile hardware had some peculiarities, like YUV color space, video planes, roller registers, square wave and noise generators, 50 Hz display, only 128 writes/scanline...
It features 10 levels with different but crappy pixel gfx, repeating very bad music (turn off speakers), 4 different (2 of them only look different) enemies (they all just go or fly back and forth, except one), 1 weapon (which is neither of much use nor necessary to win any level),... that's about it, but it was lots of fun for me creating this game .
The newest version doesn't use the emulator anymore, but works with Allegro directly.
Complete walkthrough:

Screenshots of title, and first level: