Forget for a moment about debating what happens to horror's impact (opens in new tab) whenever another player enters the scene. When you open a murkily lit doorway framing a pitch-black hallway seething with malevolent abominations of shadow, you'll want someone close by to cling to...or a giant, stuffed teddy bear. The Black Snow (opens in new tab) mod for Half-Life 2 is sadly bear-less, but its new co-op mod-in-a-mod revisits the atmospheric creepiness with up to four players and up to four pairs of pants ready for wetting.
Piggybacking (with permission) on the original single-player Black Snow (opens in new tab) , the co-op mod adds a few necessary communication binds such as a character, radio, and inventory key. You're also equipped with a flashlight, since foraging for items in the dark sort of gets easier when you have a bit more light. That's just me, though.
The objective in Black Snow's co-op stays the same: gather items, solve puzzles, and
fight bravely run away from Very Scary Things. As part of a response team sent into the eerily silent Amaluuk Research Station housed within the icy grip of Greenland, you need to figure out what happened, where everyone went, and oh my God what is that thing runrunRUN.
If you're ready, head over to Black Snow co-op's website (opens in new tab) and give it a download. Be sure to grab your nearest teddy-friend for support.