Codex Gamicus


Zero Tolerance was one of the very few First person shooters made for the Genesis. The player, after choosing one of five Marine team members (each having their own set of attributes) to start their mission with, must make their way through several dozen levels, wiping out alien and human killers that have infiltrated several areas of the Planet Defense Corp's operations.

There are three main areas of the game, each having several levels. Living up to its name of "zero tolerance", it is in the player's best interest to track down and destroy each and every enemy in a level; if the player does not destroy all enemies in a level, the onscreen enemy count will not go down on the following level and the player will not receive a password to come back to that area of the game later. Even though it can be tedious to find every enemy possible, each main area takes several hours to complete, so it is in the player's best interest to find and destroy every single enemy entity.

The player can accumulate and utilize up to five different weapons and items at once, which are displayed at the top of the screen. The middle item or weapon is the item that is currently in use, as the player can cycle through their inventory. The player's health, i. d., a portion of the map, and the viewing area from the player's visor can be seen all at once on the main screen, along with an entire map of the current level is also shown whenever the game is paused.

As the player gets attacked and starts taking damage, once their health reaches zero, that team member becomes deceased and the player must pick another team member. If all five members die the game is over.

A link cable was also available through Accolade for two players to play simultaneously, although it would take two Sega Genesis', two television sets, and two copies of the cartridge in order to be able to play in this way.


  • Move character—D-pad or joystick
  • Fire weapon or use fire extinguisher—button B
  • Toggle through inventory—button C
  • Pause/check map—Start button
  • Jump—button A+up on D-pad
  • Duck—B+down
  • Sidestep left and right—A+left or right


Major Thomas Gjoerup (Code name: "Basse")[]

Gjoerup isn't that great a shot, but he is a great fighter though. He's the toughest team member, which explains his refusing to follow orders and his being disciplined for insubordination. If the player starts a new game with this character he will be armed with a shotgun and a Bio Scanner.

Captain Scott Haile (Code name: "Psycho")[]

Haile loves blowing stuff up, as he is a ballistics expert. Not much information is available about him due to having a Top Secret background and profile. Haile begins a game with a handgun and two mines.

Captain Satoe Ishii (Code name: "Soba")[]

Ishii is the best shot on the team, as you can definitely tell the difference during combat when you use her. She starts off games with a handgun and bullet proof vest.

Major Tony Ramos (Code name: "Weasel")[]

Ramos is best at hand-to-hand combat, due to excelling in martial arts, and is sneaky, which is probably why he begins games totally empty-handed (!).

Major Justin Wolf (Code name: "Jjwolf")[]

Wolf earned tons of medals while in service. He is a crack shot, and also has medical training, which is why medipacks give others 20 health points back when injured, but with him it's 25. He begins games with a handgun and Bio Scanner.

Weapons and items[]

  • Bio Scanner—detects life forms as far as can be seen on the map, unlike with the built-in scanner on the map that only alerts you (for the most part) when an enemy is within attacking range or in an adjoining room or area. Duration: time-based
  • Bullet proof vest—withstands damage (for a while) from weapons, bite and headbutt attacks from creatures, although with every hit you take the vest's efficiency goes down by 10%. Duration: depends on damage; usually 10 direct impacts
  • Fire extinguisher—extinguishes flames. Duration: 10 uses
  • Fire suit—allows the player to walk through fires unharmed. Duration: 10 uses (usage goes down 10% every time the player walks through an area of flames)
  • Flame thrower—shoots a wall of flame around a small perimeter. Duration: 10 uses
  • Flashlight—illuminates areas. Duration: time-based
  • Hand grenades—can take out multiple enemies in a fair-sized area. Duration: one use each
  • Handgun—unlike the "crappy little pistol" in the similar-themed game Doom, these usually take out enemies without much of a problem. Duration: up to 99 bullets
  • Laser aimed gun—has a range finder for accuracy, and is fully automatic when the fire button is held down. Duration: up to 99 shots
  • Medipack—increases the health of a player up to 20 points when used, or 25 if the player is using Wolf. Duration: one use
  • Mine—does devastating damage to a fair-sized area. Once dropped by a player, they become armed, and the next time they are approached by either the player or an enemy they will explode. Duration: one use each
  • Night vision—lights up darkened areas. Duration: time-based
  • Pulse laser—these are very accurate and hardly ever miss a target. Duration: up to 99 shots
  • Rocket launcher—launches projectiles that can travel a very good distance until they hit a target or wall. Duration: up to 99 rockets
  • Shotgun—a good all-around weapon, usually a favorite in general among Fps players. Duration: up to 99 shots

Areas, enemies and items[]

Area one: Planet Defense's Europe-1 Space Station[]

The first area of the game is the Planet Defense Europe-1 space station. Most of the levels in this area are wide open in general, although the later levels become maze-like. The Greenhouse levels, due to the vegetation and moisture in the air, are foggy and have some limited visibility.

The player faces humans armed with handguns and giant crab creatures that attack by biting the player. The boss in the final level seems to be a person in a blue mech-like suit with a flamethrower for a weapon.

The only weapons and items to collect include handguns, shotguns, flamethrowers, pulse lasers, bullet proof vests, night vision glasses and Bio Scanners (note: medipacks can be found in all areas of the game).

Area two: High Rise Roof Top[]

The player starts on the top floor of the Planet Defense Core building, then works their way down from floors 164 to 151. The first few floors (not counting the roof top) consist mainly of big rooms connected by long corridors, but most of the floors afterwards are spacious, although again visibility is limited on some of them due to raging fires that can be found.

In this area, the player faces fast-moving robots with laser-aimed guns, which are thin and can be hard to destroy. They also have a tendency to gang up with other fellow robots and/or other enemies as well. Humans are also present again, but armed with laser-aimed guns and hand grenades in this area. There are also aliens with an eye in the middle of their heads that use guns and red dog-like creatures that usually attacks in packs: if you chase after one, chances are pretty good there will be at least one more charging at you from another angle.

There are also security proximity alerts that, if you get too close to one without destroying it, it will emit three warning beeps, then sound an alarm, which will cause a nearby doorway (or more) to open up, and whatever enemies are inside will come pouring out. There is also another additional security force or some kind of a sniper on the rooftop, since there are several spots where some kind of projectiles automatically hit the player when they enter the area, causing damage in the process.

There are also a few encased areas without a door that can't be opened unless the player allows a security alarm to go off, which they can just pick off the enemies then, or if it's a very small, enclosed space, the player can use the rocket launcher and batter the enclosure with a few shots, and that will kill whatever enemy is inside that area then.

The boss of this area looks like a giant lizard in an Aliens-type exoskeleton that uses a pulse laser.

Most items can be found in this area, with the exception of flame throwers, grenades, handguns, and night vision glasses.

Area three: Planet Defense Corp basement[]

The alien forces have retreated to the basement of this building, which has over 10 levels. Many of the levels are flat-out mazes, although several of the final ones are like the first levels of the second area where there are several big rooms connected by long corridors. Again, several areas are foggy due to fires.

Humans, the one-eyed aliens, the red dog-like creatures and crabs all make a return in this area, and the only new enemy are what looks like giant locusts with appendages that protrude from their heads to attack the player with.

All weapons and items can be found in this final building, and the boss is a giant insect-looking creature with a pulse laser.


There is the password feature to skip levels/areas with, the ability to turn off music and/or voices if desired, and a sound test.


  • Not only does creator Technopop, Inc. say on their website that this was not only the first Fps for the Genesis, but it was also the only game for that system that linked two Genesis' together as well.
  • Whenever the map is checked, with no matter what character you're using, the same pair of [assumedly male] white, hairy hands is shown holding up the map. Apparently everyone involved in the graphics design team forgot that one of the members on the player's team is female and another one is black.
  • With the onscreen bio of Haile, there is a misspelling of an "Ordnance" he is a member of.
  • In the last area of the game, since there is no feature to keep track of where the player has been on the map, it can be difficult to remember where a person has been and where they need to go to find and exterminate the last few remaining enemies. However, if that level's Bio Scanner has already been used or the player's inventory is too full to use one, they can launch rockets or throw hand grenades in areas to help find the last remaining enemies, as the map's built-in scanner seems to double as to finding an enemy's heightened adrenalin rush, as the telltale red dot marking the enemy on the map will appear then once a nearby explosion occurs.
  • In the August/September, 1994 issue of Sega Visions magazine, the photos of the game show a totally different cast of military characters than what would end up on the actual release.
  • A sequel of Beyond Zero Tolerance was planned and made it to the Beta stage, but ended up not released commercially. The ROM has been available as a free download for Genesis emulators.


  • Zero Tolerance review (5/10)
  • Technopop, Inc. archive site, including schematics for a homemade two player link for Zero Tolerance owners who don't have the original link cable