Two characters spawn, one belonging to each player, called clones. Clones spawn from what is known as the power booth. Each power booth has a power level which drains perpetually. In order to keep the power booth's power level from dropping to zero, the players must collect power cubes, and then bring them back to their booth. Each player is equipped with a weapon called a Gibber with which to defend themselves and destroy their enemy. When a player is destroyed, he loses a portion of his power and must wait whilst a new clone is created.
When the new clone is created, the player takes control of it and direct conflict resumes. In addition to power cubes, from time to time a power-up item will appear. Collecting this will give the player one of a variety of upgrades or effects, such as an extra Gibber, a rocket launcher, or it may freeze opponents solid or reduce them to a single hit point. The game ends when all but one players have had their power level reduced to zero. The remaining player is the winner.
Gibbage was featured over a number of issues in PC Zone as Dan Marshall wrote about his experiences in creating an independent game. When the game was complete it was reviewed in Indie Zone. It received a score of 71%.