@Tanshaydar, are you really a supermoderator? Because you're attitude sucks. We get that you don't like the idea, now stop crying about it.
In any case, Amnesia co-op could work. But only if there are 2 human characters. The humans vs monsters-concept would probably never work, especially if you try to create a horror scenario. In the end, players will probably try to be good as monster/human and it will ruin the atmosphere.
Kinda referring to the Half Life mod "
The Hidden: Source". In this game, you have a team of special forces fighting against a single invisible and agile monster. Now this mod is fully multiplayer and has some potential to be really scary. If the person who plays the monster does some immersion like throwing objects, making scary noises and hanging dead bodies on the ceilings, it can be a great scary round. But this is rarely the case as the monster will probably try to win as fast and 1337 as possible.
Now on 2-human co-op. I think the only way to keep the Amnesia feel is to keep both players isolated, but need each others help. Like a lever in Players 1 room opens door in Players 2 room. And