Free games are good but good games for free are even better and this game is one of the latter.
Developed by Digital Extremes, it is a FPS game based on the comic book by the same name, it blends RPG elements and the nice modern but occult permeated world, which will remind you of those sung during the battle between good and evil in many hard rock and metal songs.
The protagonist is voiced by Mike Patton, lead singer of the metal band Faith No More, which really gives even more personality to the main character slaughter-y attitude. Yes, The Darkness II is very violent but it is part of the setting and also the major fun of the whole game, thanks to a very fast paced gameplay and explicit graphics.
The game can be obtained for free as a Steam key from Humble Store till 7pm CET of 28th march. Don't be shy and go get it! Tell your friends too since the game has a 4 players coop mode with a dedicated campaign.