I remember a few from various stages of my life (born 1984).
Seeing the demo footage of Sonic 2 in Woolworths and thinking the leaves falling down in Aquatic Ruin zone was so cool and advanced.
The original Sega arcade of Virtua Racing with the moving cars completely blew me away.
I remember my uncle loading up Cannon Fodder on his Amiga, and a REAL song with REAL music came out, along with REAL photos. I was amazed haha.
A few years on I remember a PlayStation demo disc having promo footage of the first Gran Turismo and it looked so real to me, I watched it over and over. The first Driver on PS1 looked absolutely amazing to me also.
Tap for spoiler
Also the dawning realization that you're doing something horrible by killing the colossispoiler
I'm not sure you are doing something horrible. Destroying somrthing majestic and, in several cases, benign, certainly. But you're doing it with the express consent of the greater consciousness that makes up those things. Like you're destroying a prison with particularly beautiful art on all the walls to let the prisoner out. Dormin actually holds up their end of the bargain the whole way through, and we don't know for sure if they did anything bad to make the priest's society bind them. Hell all we know about the priest's society is that it does human sacrifice, if anything I'm leaning pro-Dormin here. There was clearly once a thriving society in the Forbidden Lands and the priest's society broke a seemingly honest god into a bunch of monsters and shut the door on the place.