I don't have much to work with here, other than these facts:
I downloaded it between 1994 and 1997 on a BBS, and it was for the PC (probably DOS, don't think it was Windows). Since I was not into warez, it was almost certainly shareware. It seemed to me to be realistic (so no monsters), but I could be wrong. It wasn't a household name at all, so definitely not Duke Nukem, Quake, or anything that was a big hit. I remember being outside, then going inside into what I remember to be a lab.
Any help on a listing of those type of games released at the time would be greatly appreciated.