Shapes on a Plane (SOAP)

Shapes on a Plane is a twist on the traditional 2D arcade-style space shooter: instead of being limited to a single plane, the player fights on the outside of a cube, with enemies and power-ups spawning on all six sides. Inside the cube is a pulsating, warping sphere that slowly grows in size as it is passively charged by the currently living enemies. When the sphere charge reaches 100%, the player is destroyed and the game ends. The longer an enemy is left alive, the faster it charges the sphere, so the player must constantly traverse each of the six cube faces and destroy newly spawned enemies as quickly as possible. There is no life counter or health meter in the traditional sense, but when the player is hit by an enemy or a hostile projectile, the sphere will receive an additional burst of positive charge, increasing its size. When an enemy is destroyed, the current sphere charge is decreased by an amount proportional to the difficulty of the vanquished foe. There is no fixed end to Shapes on a Plane; the object of the game is to survive as long as possible and obtain a high score by destroying many waves of enemy forces.