1. Blood and Guts with a Severed Head on Top.
Within the first few seconds of booting up X-Men Origins: Wolverine, you'll know how relentlessly gruesome this bloodbath of a video game is. In the game's opening, Wolvie uses his triple-bladed Ginsus to butcher several soldiers, stabbing one through his skull and going Jack the Ripper-stab crazy on the bellies of two others. Wolverine then gets a shotgun blast to his torso, and the camera gives us an up close look at the gaping hole in him, which begins to fill up with flesh and muscle.
Mind you, this is all within the first couple of minutes of the game. You can also behead enemies, hack off their arms and legs, use your claws as a human-eating blender, and even ram your claws into their chests, slicing downward and splitting them open like a fish.
If you couldn't tell, Wolverine is a Mature-rated game while hardly a drop of blood is shown in the film, which has a PG-13 rating.