Hovertank 3D

Hovertank 3D, also known under a variety of other names (Hovertank, Hovertank 3-D or Hovertank One), is a vehicular combat game developed by id Software and published by Softdisk in April, 1991.

Story
Hovertank 3D is set during a nuclear war. In Hovertank 3D, the player controls Brick Sledge, a mercenary hired by an unknown organization (referred to by the game as the "UFA") to rescue people from cities under the threat of nuclear attack (largely political activists or scientists), both by the government and by large corporations. However, the cities are also full of mutated humans, strange creatures, armed guards, and enemy hovertanks.

Gameplay
The player must drive a hovertank through the levels and try to find the people Brick is supposed to rescue. There are also many enemies in the levels, who are hunting down the people as well as the player. The player can keep track of both people and enemies in the radar box at the bottom of the screen. There is also a timer that counts how long until the nuke is dropped. Once all the living people are collected a yellow teleporter appears somewhere in the level, and the player must find it to win. Then the player receives their fee, based on the number of people safely rescued, and how fast the operation was completed. All damage to the hovertank is repaired at the end of the level.

Development
John Carmack's research in the game's engine took six weeks, two weeks longer than any id engine before it. The engine written for this game was expanded upon with texture mapping to make Catacomb 3D, and then later still the well-known Wolfenstein 3D. Following the engine's completion, the id staff decided on the nuclear Armageddon theme and developed the game. Adrian Carmack is said to have enjoyed drawing the monsters and other ghoulish touches. The credits are John Carmack and John Romero as programmers, Tom Hall as game designer and Adrian Carmack as game artist.

Legacy
The source code to the game, now owned by Flat Rock Software, was released in June 2014 under the GNU General Public License in a manner similar those done by id and partners.

Impact and Reception
Hovertank 3D is a landmark in first person game graphics. Other 3D games at the time, such as flight simulators and other games (such as Alpha Waves) that had more detailed environments, were noticeably slower.