ImDoingMyPart

Definitely an action game instead of a horror game, but it's one of the best half life 2 mods I've played. Takes maybe an hour to get through. Only downside is it left me wanting more.

It's an absolutely excellent concept, but it's way too short and nothing really happens. It seems more like a tech demo for showing off really high quality VHS-style graphics in a horror atmosphere than an actual game. I would say it's more of an experience than a game.