What RetroPie build are you using?
Maybe this would be better on a new thread. I think there's a few of us interested.

I still sporadically make the mistake of losing a day to Civ2.

Oldest game I have installed (and have played in the last year) is Head over Heels - a Spectrum game from 1987 in PC remake form, and it's still a great game work of art.

Entering a room and going "I remember this", then flashing a puzzle because of a 25-30 year old memory, does give a warm fuzzy feeling.

Now I'm thinking of how dumbed-down such a game would be if made today, and it's made me sad. :'(

I recently re-installed Unreal Tournament and had some royally good fun with it! OpenTTD is also fun for a good retro-blast from time to time. Other old games I still enjoy playing are Raptor (needs DOSBox), Dungeon Keeper II and Warcraft 3.