Doom 3 is scary and fall off the bone gory. When all the monsters come, you would be afraid to move a muscle. There's a lot of blood that splatters, dead bodies lay everywhere, there's blood wiped on the floor and walls, you can't see anything (although you do have a flashlight, also can beat stuff, but you should only use it when there's no monsters), these zombies and demons pop out when you least expect and scare the crud out of you, and you can even see brains fly out when you shoot zombies in the head with a shotgun. We hear a little cussing sometimes, but not too bad. You arrive at a base and everything's calm, no monsters yet, people there welcome you and stuff, but when you get the maybe second task to go somewhere...boom, after a cut scene, the base is suddenly attacked by zombies and demons. You have a radio, and you can hear screaming and for example: "We've got 2 down and 1 wounded.", "We don't know what we're up against.". There's also downloadable mods for the game to make it gorier, enable dismemberment, add more modes, make demons look different, make the level lights bloomier, and more. There's an expansion pack to add more monsters, another weapon, and more levels to the game.
I don't have the game...yet, and I saw gameplay videos of Doom 3. There's also an online multiplayer mode including co-op play, deathmatch, and much more.