The Concussion Gun is a weapon manufactured by Gadgetron in Size Matters. It fires a shotgun-like blast of devastating titanium pellets that deal more damage the closer the enemy is. It is the weapon of choice for the Galactic Ranger's riot squad.
The Concussion Gun can be purchased immediately on planet Pokitaru for 10,000 bolts. With use, it can be upgraded to the Concussion Cannon, a weapon that fires so much shrapnel that it is classified as mobile artillery weapon on Xyxx VII. In challenge mode, the Titan Concussion Cannon can be purchased.
The Concussion Gun is a blue shotgun with a very wide barrel, with purple grips. The Concussion Cannon is a mostly purple weapon, which is longer and held by a grip on its back rather than a trigger beneath it.
The Concussion Gun is a shotgun which fires a blast over a large area, and can hit multiple enemies at once. This makes it very effective against clusters of enemies grouped together, particularly when fired from medium range distance. Early on, it is useful against most enemies, particularly smaller to medium enemies grouped together. However, later on the weapon becomes heavily outclassed by others which deal much more damage, and deals very little damage against threats encountered later in the game.
The Concussion Cannon is a flat upgrade to the area-of-effect and damage of the Concussion Gun. It has three mods available for it: the split barrel mod for 15,000 bolts, the lock-on mod for 5,000 bolts, and the charge up mod for 50,000 bolts. The lock-on mod can make it easier to aim, but as the weapon should be fired against clusters of enemies anyway, should not be prioritized for purchase. The split barrel mod increases the width of the blast radius, giving it greater area-of-effect, and adding to the strength of the weapon. The charge up mod, while the most expensive mod, is also the most useful, as it allows the player to charge up shots by holding the fire button before releasing, blasting in a straight line but dealing twice to three times the damage. This directly addresses the weapon's biggest shortcoming in its weak damage against single threats, though as it is an expensive mod, the player may choose to instead purchase another more powerful weapon first and buy the mod for challenge mode.