In Atari's Tempest, a tube forms the main geometric playfield.
Tempest was designed by Dave Theurer and released by Atari in 1981. It uses a first-person-looking perspective down a series of polygonal tunnels, with the player's claw-like shooter moving around the near rim.
Enemies approach from the far end of the playfield. The tube may be open, closed, or shaped as a polygon, and its geometry changes as the player advances through levels. This variety is why the game is often described as a tube shooter rather than a conventional space shooter.
Tempest was one of Atari's important color-vector arcade games. It also introduced the concept of selectable starting levels, allowing experienced players to begin at a later stage rather than always starting from the beginning.