While this isn't a new Saints Row game, it's the next best thing. Volition, High Voltage Software, and Deep Silver are releasing Saints Row: Gat Out of Hell, a stand alone expansion to Saints Row that will take Gat and Kinzie into Hell to rescue the main character from the series.
If you were digging the super powers in Saints Row 4, you'll be getting angelic based powers in Gat Out of Hell. Demons will be your main enemies this time around with new weapons to go along with your new powers.
Two-player online co-op will be supported and the game's coming out for the Xbox 360, Xbox One, PlayStation 4, PlayStation 3, and the PC.
Look for Saints Row: Gat Out of Hell January 27th, 2015.
