Risen 3: Titan Lords

[Googolplex]

Or you could do it like Dishonored did for example. That game had a setting which allowed to HUD to disappear when it was not "being used" and only re-pop up when it was relevant.

Hmm, no. I hate EVERY kind of HUD. This always looks like a "videogame" and not like something substantial or earnestly. For me it always destroys the image impact. If I would design a game I would completely avoid HUD. Maybe an option to enable a slim health bar. Or if it would be a racing game, some speed/time info. But I always would try to keep it as minimal as possible. HUD is a no-go for me. It's ugly and kills the immersion.