Tempest is an arcade game by Atari Inc., originally designed and programmed by David Theurer. Released in October, 1981, it was fairly popular and had several ports and sequels. The game is also notable for being the first video game with a selectable level of difficulty (determined by the initial starting level). The game is a tube shooter, a type of shoot 'em up where the environment is fixed and viewed from a three-dimensional perspective.
The object of Tempest is to survive as long as possible and score as many points as possible by clearing the screen of enemies that have landed on the playing field. The game takes place in a closed tube or open field which is viewed from one end and is divided into a dozen or more segments. The player controls a claw-shaped spaceship that crawls along the near edge of the playfield, moving from segment to segment. This ship can rapid-fire shots down the tube, destroying any enemies within the same segment, and is also equipped with a Superzapper, which destroys all enemies currently on the playfield once per level. (A second use of the Superzapper in a level destroys one random enemy.)
Enemies swirl around at the far end of the playfield, then enter the playfield and move toward the player. When all enemies in a level are destroyed or reach the near end of the playfield, the player "warps" to the next level by traveling down the playfield. The player must avoid or shoot down any spikes left behind while warping. The player loses a ship when an enemy comes into contact with their ship, shoots it or otherwise destroys it, or if the ship hits a spike while warping. If an adequate point threshold is reached, the player can earn a new ship. The game is over when the enemies destroy all of the player's ships.
The game consists of sixteen screens with unique geometric shapes, some of which are closed tubes that allow the player to loop around, while others are open fields that have distinct left and right endpoints. When all sixteen screens have been played, the sequence repeats with a different color scheme and a higher difficulty level, including the invisible (black) levels (65–80). Each sequence of levels adds additional enemies that are faster and more deadly to the player's ship. The numbered levels stop incrementing after level 99 and a random one of the 16 variations will appear after successful completion of subsequent levels.
There are five enemies in Tempest:
Flippers are bowtie-shaped enemies that flip from segment to segment. They move toward the near end of the playfield, then begin flipping directly toward the player. If a flipper lands on the player, it captures the ship and takes it to the far end of the playfield, costing the player a life.
Tankers are diamond-shaped enemies that move in a straight line. When shot (or when close to the near end of the playfield), they split into two other enemies. Several different types of Tankers exist, with more difficult and dangerous Tankers appearing later in the game.
Spikers are spirals that move toward the near end of the playfield and leave a spike behind them, then turn around and head back to the far end of the playfield. If allowed to reach the far end, they reappear as Tankers. The player must either avoid or shoot away any spikes left in the current tube when they warp to the next level.
Fuseballs are multicolored sparks that move rapidly up and down the playfield along the edges of its segments, then move slowly across segments. When at the near end of the playfield, Fuseballs can only be destroyed by using the Superzapper. They are the only enemy that cannot fire at the player, although the player is destroyed instantly on touching a Fuseball. On the linear playfields, Fuseballs will try to corner the player at the left or right by reaching the near end.
Pulsars move similarly to Flippers and can also capture the player's ship. However, a Pulsar is shaped like a zig-zag that expands and contracts, and it electrifies the playfield segment it's occupying at regular intervals (all Pulsars do this in unison). If the player's ship occupies or enters an electrified segment, it is blown apart.