Doom

Arguably, the arcade game of Battlezone was one of the earliest First Person Shooters from way back in 1980. However, Doom was what made the genre monstrously popular, as for a long time afterwards whenever a similar game came out, it was referred to as being "Doom-like" or a Doom clone (even though its predecessor of Castle Wolfenstein is really what got the genre kick-started, but Doom is what elevated it to new heights [plus it had also been called as to being a game viewed in a "behind the gun perspective" as well, along with the Doom clones]).

The game was a gigantic hit and was ported all over the place -- including for the Sega 32X and Sega Saturn -- and is still available even nowadays via "virtual" consoles/downloads.

Story
The player's character, an unnamed Marine, has been shipped to Mars, which is full of radioactive waste facilities (along with its two moons). It is also home of the Union Aerospace Corporation, which is a supplier of weapons and delves into secret projects, one of which involves an inter-dimensional space travel device known as a Gateway.

One day a panicked message comes from a base, requesting military assistance due to something very "evil" emerging from the Gateways. The player's character and several other troops had been sent in to secure the base, which now the only one left to remedy the situation is the player, as everyone else is assumed to be dead.

Gameplay
Basically the player moves their character through a bunch of 3-D levels, pretty much gunning down everything that moves and activating various switches and buttons in order to open up access to further parts of levels, including secret passageways.

The player also collects several different kinds of firepower, along with ammo for their weapons. There are also various bonuses to increase the player's health, along with armor (which both the player's health and armor rating can each max out at 200%), as whenever the player is hit by a creature or one of its attacks, runs through radioactive or lava areas without any protective gear, or is too close to a radiation-filled barrel when it explodes, they will start accumulating damage. Once the player's health reaches zero they will die and have to restart the current level they are on again (although the Saturn version has a password entry in case the player wants to start a game from where they last left off). The player only has one life, but infinite continues.

Items, health/artifacts

 * Stimpaks--raises the player's health by 10%, and maxes out at 100% total.
 * Medikits--raises the player's health by 25%, maxing out at 100% total.
 * Berserk Pak--this raises the player's health to 100% and gives them super human strength to deliver powerful blows to enemy creatures if using their fist attack (which the duration lasts through one level).
 * Health potion--raises the player's health by 1%. Can raise the player's health over 100% (which Stimpaks, Berzerk Paks, and Medikits can't do).
 * Spiritual armor--raises the player's armor by 1%. Can raise the player's armor level to over 100% (which Security armor can't do).
 * Soul sphere--raises the player's health by 100%, which can raise it up to the player's 200% maximum level.
 * Invulnerability Artifact--makes the player invulnerable to enemy attacks for several seconds.
 * Mega Spheres–increase the player’s health and armor to 200%. (Note: these only appear in the Saturn version.)

Additional items, weapons/armor

 * Security armor--increases the player's armor level to 100%.
 * Combat armor--increases the player's armor level to 200%.
 * Backpacks--upon the first time the player finds one of these, it will double the amount of ammo they can carry for each weapon, along with adding a little of each ammo type to their total. With each additional backpack that is found afterwards it will just add to the player's armor totals.
 * Blur artifacts–-makes the player mostly invisible for a short amount of time.
 * Radiation suits--keeps the player from taking damage in radiation and lava pools (which is time-based).
 * Computer maps--these shows all areas of a level, including areas the player has yet to enter, as well as most secret areas (which lasts for an entire level).
 * Keys--used to open locked doors.
 * Chainsaw--used as a weapon, but usually not a very good idea, since the player is susceptible to attack while using it.
 * Fist/pistol--the player starts the game with only a pistol, which doesn't do much damage, which defaults to using their fists when they run out of ammo for it or choose to use the fist attack.
 * Shotgun--takes longer to load and consecutively shoot than the pistol, but does more damage.
 * Combat shotguns--twice the firepower as the regular shotgun. (Note: this weapon appears in only the Saturn version of the game.)
 * Chaingun--uses regular bullets, but fires much more rapidly than the pistol.
 * Rocket launcher--launches rockets that do a lot of damage.
 * Plasma rifle--fully automatic weapon that does a lot of damage, similar to a laser.
 * BFG 9000--the slowest of all weapons to fire, but can wipe out an entire room of weak enemies, as well as dealing plenty of damage to the stronger ones as well.

Creatures

 * Former human--armed with pistols. Can be brought down with a few bullets.
 * Former human sergeant--armed with shotguns. Only slightly tougher than former humans.
 * Imp--brown beings that hurl fireballs at the player. They are only slightly tougher than former human sergeants.
 * Demon--red beings that can only attack close up by biting. Can be taken down with a few shotgun blasts.
 * Lost Soul--these are flaming skulls that float around, although they will move much quicker during an attack by ramming into the player. Again, a few shotgun blasts will take care of one of these.
 * Sceptre--same as a Demon, only barely visible.
 * Cacodemon--flying giant heads/mouths that shoot fireballs at the player. Takes many rounds from a chaingun, shotgun, or even a couple of rockets before they can be killed.
 * Baron of hell--the toughest out of all enemies to kill, these take several hits from a rocket launcher, several rounds from a plasma gun, or even a couple of direct hits from the BFG 9000. They shoot fireballs at the player. These entities are half goat, half demon in appearance.

Note: the Saturn version also has many Doom 2 levels, so all of the above, plus the following Doom 2 creatures are also present:


 * Hell Knight--like Barons, although not as tough.
 * Arachnotron-–spider--like enemies with Plasma guns. A few shots from a combat shotgun will destroy it.
 * Pain Elemental–-about the same size and about as tough as a Cacodemon, but ejects Lost Souls rather than fireballs.
 * Revenant–-a few blasts from a combat shotgun or a couple of missiles will take down this enemy, although in the meantime it fires rockets that will home in on and follow the player.
 * Mancubus–-big and can be killed with several combat shotgun blasts, but fires up to two fast-moving rockets at once.
 * Spider Mastermind–-one of the hugest and toughest enemies, which is armed with a super chaingun and takes many rockets or even BFG 9000 hits in order to kill.
 * Cyberdemon–-just as, or even worse than the above, this giant takes a ton of firepower to bring down, plus it fires several rockets at a rapid pace.
 * Nightmare Spectre–-“big bad brother” of the Spectre.

Controls (in-game, three button controller)

 * Walk--D-pad or joystick
 * Run--D-pad or joystick + button A
 * Strafe--press/hold button C
 * Open doors/throw switches/use elevators--button C
 * Scroll through weapons--press/hold button A + Start
 * Automap--press/hold button C + Start
 * Pause--Start

(in-game, six button controller)

 * Move--D-pad or joystick
 * Run--D-pad or joystick + A button
 * Fire--B button
 * Strafe--C button (press and hold)
 * Open doors, activate switches and elevators--C button
 * Scroll up through available weapons--X button
 * Scroll down through available weapons--Y button
 * Automap--Z button
 * Pause--Start

Note: controls can be changed in the Options menu.

(Automap, three button controller)

 * Activate Automap--C button (press and hold) + Start button
 * Move--D-pad or joystick
 * Zoom in and out--A button
 * Follow mode--B button
 * Grid--C button
 * Instantly scale up or down--A button (press and hold) + Start

(Automap, six button controller)

 * Automap--Z button
 * Move--D-pad or joystick
 * Run--D-pad or joystick + A button
 * Zoom in--A button
 * Zoom out--B button
 * Follow mode--X button
 * Instant scale up/down--Y button
 * Grid--C button
 * Pause--Start button

Differences with 32X version compared to PC original

 * Several levels are missing.
 * Games can't be saved.
 * The player only gets the front and back views of the enemy, never a side view.
 * Rather than enemies sometimes attacking each other, this almost never happens; there is one level where two Barons might be maneuvered into a crossfire, which is about it.
 * No "picked up a clip" messages appear, just a sound effect is heard when ammo is gathered.

Controls (in-game)

 * Attack–-A button
 * Use item-–B button
 * Strafe–-C button
 * Stafe left and right–-left and right on D-pad
 * Map–-Z button
 * Select weapon–-Y button
 * Run–-X button

(Automap)

 * Scroll-–C button + D-pad
 * Zoom–-C button + left and right on D-pad

Differences with Saturn version compared to PC original

 * The game has passwords for the player to return to a previous game save, which the original did not have this feature (it just had a hard drive save).
 * The game only has four skill levels, which the original (and Sega 32X) version has five.
 * Has most, but not all levels from Doom 1 and Doom 2.

Trivia

 * The Sega 32X version was considered by many to be a bad port because of the border around the screen. However, it scrolls well (running way better than the 3D0 version), but arguably its biggest downfall is not being able to save a game or go back to one in progress with a password feature or anything.
 * There were quite a few blown Sega 32X units among gamers, due to there only being two cooling vents on the sides of the Sega 32X, along with long games being left on pause on the Sega 32X version also being the culprit, since there was no game save or password feature for that port.