As addicting as Minecraft, but less gay
So during one of Steam's many holiday blow-outs, I bought the game "Killing Floor" on a whim.
I've clocked nearly 150 hours on it so far. I cannot stop playing it. No matter how hard I try to take a break from it... I need more.
Perhaps I'm compensating for a distinct lack of co-op survival/shooter games in my life. The last decent one I played was RE5's Mercenaries, which my friend and I played the FUCK out of.
Whereas Mercenaries got old rather fast, something about Killing Floor doesn't stop being fun. Probably because it's so fucking difficult. Not like Demon's Souls difficult, where you want to chop your own dick off in blind fury. Fun-difficult.
I'm not going to give a detailed review of this game, because honestly, there isn't much to review. The design elements are meh, there's no story, it's just "shoot mutant zombies with your friends and don't fucking die".
I recommend this game to everyone, and you should totally play a few rounds with me.