Vicdoom : Doom for the VIC-20
This is a "port" of iD software's Doom, for the fully expanded Commodore VIC-20. It's a mixture of C and 6502 assembly. C is compiled with the cc65 compiler, which you can find on github.
Features:
cut down versions of shareware Doom's levels, minus the secret level
sergeants, demons, imps and cacodemons, with AI code cut down from the Doom source
fist, chainsaw, pistol, shotgun, chaingun
health, ammo, keys, weapons, security and combat armor
corpses
exploding barrels
secrets
11 music tracks, converted from the original Doom midi files
20 sound effects, converted from the original Doom PC speaker sounds
cheat codes
panning and zooming map
intermission and victory screens
arbitrarily angled textured walls