This is currently unplayable as the six bad guys who attack you immediately do not seem to die regardless of how many bullets you pump into them. Fortunately you have an unlimited supply and they don't appear to do any damage to you! They do disappear into walls and reappear again which is a neat trick!
Also there are no turn left or right keys they all strafe - so the only way of turning is with the mouse.
I suspect this game is broken when running in DosBox, I will try it on my Win 98 PC sometime if I can be bothered.