Slow FPS or intended effect?

[Kuni]

Go into your My Documents folder (or equivalent depending on OS), find the Amnesia folder and locate user_settings.cfg in your Profile folder. Open with Notepad, find the line that says '<Debug ShowFPS=' and change it from "false" to "true".

Now you can check whether it is the fps or the style of the game

It is a rather slow paced game but some large rooms can hit fps quite hard so it might be worth tweaking the settings. Especially SSAO, Smoothing, etc.