On my Mac iifx in the early-mid nineties, I used to play a flight-sim game which allowed 5 monitors. I think it was called F/A-18 Hornet. The PC version didn't have multiple monitor support and I can't remember exactly how the set-up worked (I think code was sent to each Mac & monitor on the Appletalk network). Anyway, the advanced multi-media capabilities of the Mac allowed for some great multiple monitored games. But those 21" CRT colour monitors were hellishly expensive!
I placed three monitors, one on top of each other; Lower, angled up>For Cockpit controls/Joy/, Middle>Forward facing through flight-deck window and HUD, Upper, angled down>overhead view (out of the sun attacks). Left and right monitors angled in for left/right view.
We'd spend hours playing after the office closed. In a darkened room It was quite immersive as the system had four channel audio as well. Ah, the days when Mac's had some great in-built gaming technology and devs who took advantage of it.