Gun Mayhem is a platforming shooter, featuring various modes, single-player and co-op gameplay, customizable characters and a whole slew of weapons to unlock. In the game's main campaign, you progress through levels by killing your opponents until the winning conditions of each match are met. To kill your opponents, you have to blast them off the screen with your firepower. You obtain weapons from crates that fall from the sky. There are also power-ups, which will appear in bubbles. In addition to the campaign, Gun Mayhem allows you to create a custom game that supports up the four players. There four modes to choose from; Last Man Standing, Duck Survival, Gun Game, and 1 Hit 1 Kill.