Torus Trooper is a fast paced arcade-style game created by Kenta Cho , who is also known for his work on Tumiki Fighters The game is similar to that of the classic arcade game Tempest in that it is a tube shooter. It also has elements of racing games, as the player is moving along the tube, and has a time limit instead of limited lives. Torus Trooper was coded in the D programming language and was released as open-source freeware. As it is open-source it was compiled for Windows, Mac, and Linux
Torus Trooper has the player (a ship) flying through an infinite tube as high speeds. The player must shoot large amounts of incoming enemy ships, who will fire their weapons at you. Two weapons can be used to dispatch them. Your main weapon is a machine-gun like cannon, which will increase its potency with prolonged use. Your secondary weapon is a charge shot than can shoot forward and take out multiple enemies. Both weapons have unlimited ammo.
After a certain amount of points are scored, the player will encounter a boss ship, which takes a larger amount of hits to kill than the usual enemy and also has more difficult bullet patterns. After killing the boss enemy, a new level will start that is faster and harder.
A time limit ticks down as you play, and the game ends when it runs out. Time can be added through achieving a certain amount of points or defeating boss enemies. Time is added in increments of 15 seconds for points, 30 for mid bosses, and 45 for main bosses. Dying, while you have unlimited lives, will impose a large time penalty.