The Grenade Launcher is a medium-sized, black, handheld weapon with a round, revolving cylinder magazine, a barrel with a grip, and the weapon's primary grip on the rear.
In gameplay, the Grenade Launchers can only be found in certain Stages, such as Lost Impact. They can be wielded by enemies aligned with GUN, such as GUN Soldiers, who will use them against the player.
Grenade Launchers can be dropped by defeated enemies that wield them or released from breakable Containers. Touching one will make the playable character pick it up automatically, and pressing // (whether on the ground or in mid-air) while using the crosshair to aim will fire it. As a cannon, the Grenade Launcher can eliminate surrounding obstacles and enemies with an explosion. By comparison to other weapons, the Grenade Launcher has a short range and medium damage output. A Grenade Launcher has a total of six shots, and once those run out, it becomes useless. However, it can be reloaded with another six shots by picking up another Grenade Launcher.
- The Grenade Launcher is modeled after the Milkor MGL.