Wario on a friend's gameboy, I think
Close runner up is FF8, not knowing what it even was at the time, but thinking it was mindblowingly photo-realistic.
Or maybe Civ 2 that was installed on a 2nd hand PC we got (until one day I got the bright idea of deleting it, and losing it forever)
When I was a kid, I love war games or any games that has tanks on it. So the first game I played during that time was Battle City. it's a tank game where you gain upgrades by picking up stars. It also has other powerups such as extra life, shield, and instant enemy kill. This is one of the best game I played.
I've already answered before, it was Mario Brothers on NES but I've just saw the thread again and I figured this time I'll answer the first PC game I remember playing.
I would guess around 1993 or 1994 we went to my uncle's house for dinner and he had a brand new PC with DOS and some shareware games. The 2 I remember playing that day were Prince of Persia and Wolfenstein 3D! These are the first ones I remember playing, and a year or two later when my family got our own PC I of course promptly brought disks over to his house to copy those shareware games for myself! My uncle was the guy who got me into PC gaming, and was a source for getting a lot of my earliest PC games. One I remember from another, later visit, was Hugo's house of horrors. My cousin knew how to beat it so she showed me how to beat the entire game, and then copied the disk for me. I later got Hugo 2 and 3 , and figured out how to beat the 3rd game but I've still to this day never beaten Hugo episode 2.
I remember playing on an orange Binatone console connected to a TV at a friends house. The only games I played were tennis and football in glorious black and white. This was in the mid 70's. My first gaming machine was a Sinclair Spectrum 48k and I would spend ages loading games on compact cassette in a tape deck. I loved Atic Atac by Ultimate Play the Game and Elite by Firebird. Keen to explore the new Elite Dangerous on PC.