Mass Shotgun

 is a gun that fires a large, slow projectile that will split up into a barrage of 12 small projectiles shortly afterwards.

Synergies

 * If the player has Mine Cutter, when the Mass Shotgun shot splits, 6-10 piercing Mine Cutter lasers will be fired in a cone in the direction the shotgun was fired.
 * If the Mass Shotgun shot hits an enemy before it splits, the lasers will not fire.
 * If the player has Stout Bullets, Fat Bullets, or Heavy Bullets, the Mass Shotgun's shots become extremely large.
 * If the player has Badge, the police officer turns into a robot and becomes invincible.

Trivia

 * This gun is a reference to the Mass Effect series' collapsible weapons.
 * While it does not have a direct counterpart in Mass Effect, the Mass Shotgun is somewhat similar to the Geth Plasma Shotgun, which shoots 3 plasma pellets when uncharged and 1 plasma slug when charged. The colors of the shots are also green on both guns.
 * This might also explain the synergy, since the Geth is a robotic race.
 * The tagline references a side quest in Mass Effect 2, where the player, as Shepard can choose to sponsor a store with the line "I'm Commander Shepard, and this is my favorite store on the Citadel."
 * The synergy likely references the fact that both Dead Space and Mass Effect are published by Electronic Arts.
 * The synergy is also a reference to Mass Effect.