Silent Hill: Alchemilla is Source Engine mod that tries to marry Silent Hill's engrossing atmosphere with a combat-free design.
Alchemilla is made by talented modders who remember the classic Silent Hill games for what they did best: gloomy atmosphere and a general sense of uneasiness.
The mod's Moddb page even says as much.
"So we have an ADVENTURE type game in Silent Hill universe with NO MONSTERS and NO GUNS, MELEE. We wanted to implement these features strong enough and we searched for people for the last days and sadly didn't find any who could help us to do this quite well. It is very sadly for us too. We don't apologize for this cause we did all what we can," reads the description.
"In our game you will not find inventory system or notes system and the reason the same - there are no people who could do that on Source engine (people start to hate it cause it outdated). So just sit tight, take pen and notebook and play as hardcore gamer, make notes yourself, draw your maps yourself. If you Silent Hill fan - you should deal with that."
Give the trailer a watch to see what they're going for.
If you would like to see what a horror adventure game might be like (that isn't called Five Nights at Freddy's), all you need to run the mod is a Steam client and a version of the Source SDK.