Shank is a side-scrolling fighting game starring the titular character, an ex-mob hitman. Shank wants to avenge the death of his girlfriend, who was murdered right before his eyes by a gang. He has to run and jump through levels while killing hordes of enemies and bosses in the end of each. The mechanics are based on three weapon types; a pair of knives, melee weapons such as machetes and chainsaws, and ranged weapons such as shotguns and double pistol. Each weapon type is bound to a different input button. He often has to fight off many enemy at once as the different attacks can be linked into combos. Defeated enemies also drop weapons that can be picked up. Items in the environment can be used for acrobatic maneuvers.
For multiplayer there is a separate campaign that is played locally with another human player who takes the role of Shank's partner Falcone. The multiplayer campaign levels are built around cooperative gameplay to defeat the enemies and bosses. The story of the multiplayer campaign acts as a prequel to the main game storyline.