Doom II: The Monster Invasion
One day, you got up for work, expecting the usual day in the life of a space marine. You, however, encounter the complete opposite, as Hell had other plans, by abusing the teleporters again, invading all of UAC, turning the tables on them. Now, only you remain, and Hell's forces are reigning; It's up to you to kill all of the monsters by yourself, showing them just one space marine can overthrow armies!... That is, if you are up to the challenge. There may be a demo sometime. Get ready, Marine!
This hack requires ZDoom or GZDoom, although GZDoom will show the full potential of this hack, with true color, while ZDoom will downgrade all the visuals and remove all the 3D models.
F1 brings up the story for the current level. Try using Alt Fire on certain weapons to do different attacks!
A demo of an earlier version of this hack is downloadable here. Note this is before all levels were redone.