Killing Floor is an acquired taste, or at least it was for me, like chugging down a bucket full of rust and blood, with accents so dodgy they’d taken on form and floated atop the grungy broth like cockney croutons. Where Left 4 Dead directs the players’ progress, toying with them, Killing Floor has the player run around in circles, waggling their most succulent parts at the mutants and freaks, encouraging pursuit. Crowd control, herding, elimination; it’s a butchery simulation with cattle that bite back. This summer’s special event, the Summer Slideshow 2012, adds new levels, enemies and guns. The trailer would have given me nightmares when I was a boy.