Having some generic monster chase in a generic corridor would dissolve all of the tension. You know where he is (behind you), you know what he's going to do (chase you), and you know what he wants (murder). There's no tension there and no fear. Just you, a corridor and a monster. Whoopdee fucking doo.
There's a reason why games like Amnesia have "hide in the corner" sequences rather than "oh no monsters run!" sequences. It's because the tension of hiding is frightening, while the exhilaration of running is just boring, generic action-movie schlock. They might as well just give you an assault rifle and tell you to be scared, like every other "survival horror" game out there.
I don't see how 682 would be any different from Amnesia monster. It's an unkillable entity that stalks the corridors that you need to hide from. When it chases you, your shit will exit your anus as you look for a place to hide from it.
Edited:
Listen.
I'm not explaining to you what scares me. I'm explaining to you the formal concept of tension in a work of fiction. Tension is the most important aspect of legitimate horror. Think about every monster movie ever. When did it stop being scary? Right around the time you finally got a good look at the monster.
Action sequences, fight-or-flight responses and chases are not scary because they completely dissolve the tension. There are no lingering questions. No doubts as to what you should be doing or where you should be going. Just "monster here, salvation there. Go."
I'm not saying there's one single way to scare people. I'm saying there's one single way to illicit long-lasting fear, and that's tension. You can invoke tension in a plethora of ways. Mystery, self-doubt, paranoia, atmosphere, ambiance, pacing, etc. Benny Hill chases aren't one of them.
Can you not have SCP 682 as well as chase scenes?
You're spewing shit, there's literally no reason SCP 682 can't be scary. Seems to me you're just looking at it on paper and not imagining what it would be like in the actual game, where you'll be immersed into the atmosphere and ambiance.