Yep, M.A.X. is one of my favourites - the unit designs were fun, too - and yes, the GOG DosBox version runs a treat. Ah, my swarms of up-gunned and up-armoured Recon Trikes swarming across the tundra ... good times! Still fire it up occasionally for a game (though less often since I found Megamek!)
My original gaming machine was a ZX Spectrum 48k 'rubber-thumb' ... and one of my throwback favourites on that was Rebelstar, which was a direct ancestor of the UFO games. The map was large enough that to reset the unit positions to play again, you had to reload the game (hoping to avoid the feared 'R TAPE LOADING ERROR' message) - if the 'unit size' was an inch square wargaming figure, the base map would be five feet by eight (yes, I drew it out). And the rebel characters were named in tribute to a number of science-fiction heroes, with very slight spelling changes ...
On a previous PC I had a Java clone of Rebelstar that I'd found somewhere, which replicated it fully, but that machine died and went down with all hands. Still miss burning through one of the airlocks as a distraction attack before sending the rest of my forces through the airlock furthest from that once the defenders had relocated, with a mad dash through the mining bay to get to the computer centre ...
(There was a sequel that in no way [cough] borrowed ideas from Alien, where some of the same characters reappeared, trying to get to their rescue shuttle on a hostile planet that unfortunately seems to also host some rather dangerous organisms. Rather higher difficulty level!)
And then, for PC gaming, there was Myst (still got that, too) - the immersion of switching off the lights, turning up those beige desktop speakers, and wandering around that island and the associated Ages, with the gentle lapping of water ...