The player controls the protagonist, Snake Logan, a top CIA operative. Upon receiving reports of Metro City being invaded by mutants, Snake is ordered to fly recon over the city. However, after crash landing in Metro City, Snake is forced to complete his mission on foot.
The game has three episodes, the first of which was released as shareware, the rest being available commercially. The episodes are:
- Episode 1 - Dr. Mangle's Lab
- Episode 2 - The Hidden Lab
- Episode 3 - Master Cain
Sales of the game were discontinued in 2000 due to problems with more modern operating systems.
Apogee released the game as freeware on December 23, 2005 as a "Christmas present" and the full game can be downloaded from the Apogee website. It is likely that this decision was made due to the results of an earlier poll on the 3D Realms forums, where visitors could pick a game they would like to see released as freeware from a list of discontinued Apogee games. See also list of commercial games released as freeware.
This Video Game contains examples of:
- '80s Hair: Snake's permed mullet in all its eighties glory, combined with a Badass Mustache, gives him a cheesy eighties Action Hero look.
- Adorable Evil Minions: Most of the mutants are oddly cuddly looking with big cartoony eyes.
- Attack Drone: Robo-buddy serves as one.
- Big Bad: Master Cain
- Boss-Only Level: Applies to most of the bosses. The Enforcer, the last boss of Episode 2, is an exception.
- Bound and Gagged: The Hostages in the 2nd and 3rd games (except for Commander Keen)
- The Cameo: CommanderKeen is one of the hostages that Snake rescues in the second game. To Keen's chagrin, Snake mistakenly calls him "Captain" Keen.
- In Episode 2, Level 10, Jim Norwood, George Broussard and Scott Miller from Apogee are hiding in one secret room.
- Damsel in Distress: The female hostages.
- Disc-One Final Boss: Dr. Mangle, who is the Big Bad of the first game, but - in a surprise twist - not of the series
- Distressed Dude: The male hostages.
- Easter Egg: In Episode 2, Level 10, there is a secret room where the developers of the game are, as well as characters and items from some id and Apogee games.
- Enter Solution Here: Some levels have puzzles where five switches must be pressed in the correct order to get bonus items. This right combination is revealed in another part of the level. The player has only one attempt to solve the puzzle. If they fail, there's sometimes a punishment. For example in Episode 1, Level 4, the platform Snake stands on (when pressing the switches) will disappear and he will fall into a pit full of spikes.
- Fallen Hero: Master Cain was once a secret agent, who went rogue after he believed he was abandoned.
- Giant Space Flea from Nowhere: Skull Man is the odd one out compared to the robots, mutants and masterminds Snake fights. It's unclear who he is or why you're fighting a blue-skinned giant sitting on a throne in a cave.
- Greed: Dr. Mangle's motive, combined with being threatened by his employer.
- Interchangeable Antimatter Keys: There are locked closets in many levels, each of which opens with any single-use key. Most of them contain bonus item but some may have shards that are needed to open locked doors or turn off force-fields that block the path of the player.
- Karmic Nod: As he lays dying, Dr. Mangle mentions that he believes that "I have gotten what I deserve for my crimes."
- Life Meter: Both the player and the bosses have this in the bar format.
- Lighter and Softer: In a sense, the second and third games. The first game was set in the aftermath of a terrorist attack, and the levels included dead (and in some cases, scorched and decaying) bodies scattered throughout several levels. The second and third games were infiltration missions to prevent further terrorist attacks and, thus, Snake doesn't stumble upon any corpses. Of course, the second game also includes an attack that is done by the Big Bad as retribution for Snake's interference, which is said to have killed thousands.
- Locked Door: Most levels have at least one door or force-field that must be opened or turned off with a crystal shard or a keycard.
- Ludicrous Gibs - The mutants die this way.
- Mad Scientist: Dr. Mangle.
- Mood Whiplash: The first game has Snake wander among the ruins of a town attacked by terrorists and encounter bodies of dead Innocent Bystanders while shooting at rather cartoony-looking mooks and making snarky one-liners to the survivors he rescues.
- Non-Standard Game Over: If you try to leave the final level of the second episode without acquiring the nuclear bomb and planting it in the spot just before the exit, Snake will be killed and the Big Bad will win.
- One-Winged Angel: Dr. Mangle and Master Cain. The former fights Snake as a toad-like mutant, while the latter may occasionally turn into a blue phantom that performs a One-Hit Kill on Snake if he touches him
- Revenge: Master Cain's motive. He was an agent who was not extracted, and blames the US government for leaving him behind.
- Robot Buddy: It's even called "Robo-Buddy" in some versions.
- Secret Level: At least one in each episode, the player must collect special Secret Level Gems to access these.
- Shapeshifting: Snake is able to transform into a mutant in the second game in order to solve a specific puzzle (and then transform back once said puzzle is solved).
- Shareware: The first Episode was originally released as shareware, Episodes 2 and 3 being commercial. The entire game was released as freeware in 2005.
- Commander Keen is one of the hostages.
- Episode 2, Level 10 has a statue of Yorp, an enemy character from the first Commander Keen game.
- A secret room in Episode 2, Level 10, has lots of shout-outs, including characters and items from Commander Keen, Monster Bash and Duke Nukem, logos of Apogee Software and id Software, as well as cameos of three Apogee staff members.
- Spiritual Successor: Bio Menace feels very similar to Duke Nukem I, an earlier shoot-em-up platformer that was developed by the same company.
- Symbol Swearing: In the ending of Episode 2, the Big Bad calls Snake a "son-of-a-&*^%$".
- Taking You with Me: Master Cain tries to do this with Snake by detonating his suit, but fails.
- Those Wacky Nazis: Mangle is clearly named after Third-Reich scientist, Josef Mengele.
- Your Princess Is in Another Castle!: Yay! Dr. Mangle's dead! But why did the developers have the guy who is clearly the Big Bad die in the first episod-Oh...