We played network Doom on NeXT workstations in 1995. Playing videogames on PCs was strange enough, but networked play was something else. There was a Sun E1000 server holding it all together. We were testing overnight batch processing, which involved about an hour of work, then 7 hours of total boredom watching it run through.
By the end of that project we had the level editor running, and had built a very good facsimile of the office, complete with lifts and security guards at reception - we had them as those brown fireball throwing things.