Ah, ok
I never liked STALKER, I found it boring, so sold it.
Do you mean the 2D Wolfenstein that came out just before DOOM or the newer Wolfenstein?
The middle one I mean, circa 1999 I think.
If so yes, that can be quite hard, especially one Monster about two thirds through the game and also those black-clad women soldiers who are very very quick.
If you're having probs play it on easy setting. Or cheat
It's possibly my favourite ever game, that Wolfenstein, played it through again just a couple of months ago.