Weapons of Saturn is a mod made and released by Lippeth in 2013 and can be played on ZDoom.
The mod adds new weapons (or modifies existing weapons). For example, the pistol is weaker but fires faster and it has swapped hands. The shotgun and rifle have aiming down sights and most weapons now incorporate a reloading mechanic. The BFG9000 acts differently to how it normally would, with the primary fire mode being similar to that of a plasma gun with more powerful projectiles, while the previous fire mode has now become its secondary.