re: First video game that blew your mind

I'd say there have been a couple of iterative leaps, but the OG Zelda on NES was definitely the first that got me hooked on long-form adventure games.

Dragon Warrior (NES) was my gateway drug to RPGs, but

Final Fantasy (NES) was the game-changer. I tried to beat it with practically every combo of classes. Eventually, my save file data got corrupted and weird stuff started happening, like a Gas Dragon showed up super early in the game (like first 4H early) and it had area-appropriate stats. When I killed it, it gave XP & G like it should in the end game, and my party's level up music went for about 5 mins.

Next Gen SNES - FFII (IV) The scope of the game was amazing, but the soundtrack really was the game-changer. Little easter eggs like getting the quest chain to go back and forth to get frying pan to exchange for the spoon, just to throw it at the end boss was amazing.

I'm an RPG junkie, so FFIII was pretty epic, too. Particularly with points in the game where you could permanently gain/lose party members.

PSX - Metal Gear Solid & VR Missions - The sniper rifle in this game was my favorite wrinkle. It was nice to have a MG game that didn't make you want to rage quit.

Final Fantasy Tactics - The depth of the game, along with the class system was very much a game-changer, IMO. I took a couple of sick days at work to play FFT nonstop.