Doom 64

Doom 64, released March 31, 1997 for the Nintendo 64, is a sequel to Doom II, though it is not universally accepted as part of the official Doom canon. Doom 64 was released by Midway, in cooperation with id Software.

The plot focuses on events following the original games in the series. An evil entity known as the Mother Demon has survived and brought back the decaying dead creatures you once killed. It is up to you, the lone space marine, to stop the legions once again.



Story
Quoted from the Doom 64 manual:

Your fatigue was enormous, the price for encountering pure evil. Hell was a place no mortal was meant to experience. Stupid military doctors: their tests and treatments, were of little help. In the end, what did it matter - it was all classified and sealed. The nightmares continued. Demons, so many Demons; relentless, pouring through. Far Away... The planetary policy was clear. An absolute quarantine was guaranteed by apocalyptic levels of radiation. The empty dark corridors stand motionless, abandoned. The installations sealed. The Present... A long forgotten relay satellite barely executing, decayed by years of bombarding neutrons, activates and sends its final message to Earth. The satellites message was horrific, from the planetary void there came energy signatures unlike anything sampled before. The classified archives are opened. The military episodes code named "DOOM" were not actually completed. A single entity with vast rejuvenation powers, masked by the extreme radiation levels, escaped detection. In its crippled state, it systematically altered decaying dead carnage back into corrupted living tissue. The mutations are devastating. The Demons have returned even stronger and more vicious than before. As the only experienced survivor of the DOOM episode, your commission is re-activated. Your assignment is clear: MERCILESS EXTERMINATION."

Gameplay developments
Enhancements were made to the computer Doom engine for use in Doom 64, and gameplay elements were altered to increase the sense of fear evoked in the player. Doom's core gameplay, however remained the same: the exploration of demon-infested corridors, looking for keycards, switches and ultimately the map's exit while surviving deadly traps and ambushes.

Key differences from the computer games in the series include:
 * 32 exclusive new levels.
 * New, larger sprites for all enemies, items, weapons and projectiles which were anti-aliased when close to the player to prevent pixelation.
 * No Commandos, Arch-Viles, Spider Masterminds or Revenants (removed due to the limited storage capacity of Nintendo 64 cartridges).
 * The Nightmare Imp and Mother Demon were introduced as new monsters.
 * All new textures, scrolling skies, room-over-room architecture, and custom scripting.
 * Eerie synth ambient music tracks (instead of MIDI rock music)
 * More ambivalent usage of Satanic imagery (inverted pentagrams, inverted crosses, depictions of sacrifice) than the computer version of Doom with differing usages of horror schemes.
 * More advanced atmospheric colored lighting and effects (until Doom 3, Doom 64 possessed the best graphics of all Doom games).
 * The player's viewpoint is from chest level, rather than eye-level, making all objects and characters appear larger in relation to the player.

Weapons
All the weapons from the original computer game are present, but redrawn (Fist, Chainsaw, Pistol, Shotgun, Super Shotgun, Chaingun, Rocket Launcher, Plasma Rifle, and BFG 9000) with new sprites (the chainsaw was given two blades instead of one). A new weapon known as the LaserGun (referenced in-game as "What the !@#%* is this!") or the Unmaker has been added. It was first mentioned in the Doom Bible and was planned to be featured in the computer Doom games but never appeared. Its appearance in Doom 64 is its only official appearance, and with the power of three ancient artifacts (known as "Demon Keys") found in the game, it becomes more powerful by additional beams with each key found.

The Demon Keys are also a means to clear MAP28: The Absolution quicker: Each teleporter in the map has a symbol representing each key behind them and if the player has the right key, the corresponding teleporter is disabled.

Maps
Doom 64 featured 32 original levels:

Computer conversion
Since the release of the Doom source code for the computer games, programmers have created feature-enhanced versions of the computer Doom game in their own source ports. Several fans of Doom 64 decided to work to convert the game's exclusive content to the computer using jDoom, generally considered the most graphically advanced of the source ports. The add-on, titled "Doom 64: Absolution" is available for download and features the new graphics and maps of the Nintendo 64 game. It is a near-perfect translation of Doom 64 with new content of its own. It appeals to many fans as a way to play through the game on a computer without using emulation.