Welcome to "HacX: Twitch 'n Kill" by Banjo Software! Developed and released in 1996, HacX was a critical and commercial failure at the time of release, mostly due to Quake and Duke 3D being released in the same year, causing everyone to stop caring about Doom for a while. Even those who purchased it complained of terrible level design and severe glitches.
Luckily, HacX was re-released on October 9, 2010, with a new 1.2 update! This update fixed numerous glitches as well as isolating HacX to it's own standalone IWAD. HacX is now free from the HacX website and does not need Doom II to run. All you need is a source port (ZDoom works best). This is a fantastic game that you should definitely try for yourself:
Story (from HacX website):
"Okay. So you're going along, minding your own business, which just happens to be hacking into other people's databases, when your latest hack, some hi-tech company, catches you on-line and sends over some government jerk to arrest you. Mother said there'd be days like this. You broke a few national and international laws. So what's the big deal?! Hacking is what hackers do! But seems like you hacked into the wrong database this time. Ultra-secret and all that. Genemp Corporation. Some biotech something or other. Database called itself GENIE. Something peculiar in that. Awfully sophisticated database. Especially if it caught you in the middle of hacking, and you're the best, it's eerily sophisticated. Like it can actually think, or something.
So they send you packing... to the federal pen. For the rest of your natural life. No computer, no gear, nothing. Total drag. Cement and bars, and the other guys inside aren't exactly your average beefcakes. They catch a glance at your cyber-jockey derrière and get a wet gleam in their eye. So what you do for the next twelve months is hit the weight room--hard and fast! You pump iron like your life depended on it--and it does. You learn to sleep with one eye open. Punching the heavy bag becomes your breakfast; tae-kwon-do your lunch, and for dinner... well, you gotta eat sometime. And practice? Plenty. 'Cause these boys got a gleam in their eyes that won't go away. But how you've changed! Over once scarecrow arms, muscles wrap tight and heavy, and you've got a fu-kick that makes the boys call you "Sir". Before you were just an average pencil-necked geek, now you could grace the front of Muscle and Guns Magazine. And just in time, too.
Because one day you return to your cell to find a tight-lipped, little man in a black suit with a bad haircut. Won't give his name, but says he's a Government Agent with the Subcommittee. Which subcommittee? The Subcommittee. The guy's a regular riot; just one clown shy of a circus. But you listen, 'cause heck, you've got all the time in the world.
And so he tells a tale.... of world-wide communication blackouts, computer network shutdowns at governmental and military installations, international stock market crashes, and what might seem unbelievable.... armies of cannibal zombies roaming the globe, laying waste to everything in their path! Nothing fancy, just your everyday global chaos. The President has declared martial law, but they've lost contact with parts of the armed forces, and some of these rogue military units are assaulting urban centers. The country is being decimated!
And you thought you had it rough! So, why tell you? Because you're the best Hacker in the business. And they think they know who's behind this weirdness--a consortium of powerful, international hi-tech conglomerates, but they can't get close enough to be certain. So far every government agent they've sent in has yet to return. They need you to infiltrate these corporate databases and find out what's going on. What's more, they want to surgically install a military-grade Genemp Microtel into your frontal cerebral lobe. A what, where? A new, experimental cyber device that allows you to cyberleap from one terminal to another using cyberspace as if it were a taxicab.
So what's in it for you? You get to keep the Microtel and have lunch with the President. You laugh, 'cause you've heard better offers from the guys with the gleam in their eyes. Oh, he adds, there's $20 million in gold. Suddenly you feel patriotic. Ah, why not?
There's only one hitch to getting the gold, the Agent says. What? You gotta stay alive."