“Moment that shocked you the most in any video game”
This is one where I knew what it was going to be right from the beginning. I was playing an RPG that blurred the line between fantasy and sci-fi, and around the mid-point of the game, all of a sudden my favorite character was killed!
The rest of the party getting wiped out isn’t supposed to happen storywise, but that is a pretty tough fight. And no, you can’t save Nei by having her win the solo fight, though the explanation for why she dies anyway got lost in translation.
Actually, Phantasy Star II has two additional shocking moments after that, twists that, to someone playing the game now, would be even more shocking because fewer games have tried to replicate them. The destruction of a planet from the first game, and the reveal of exactly who the true enemies are. The ambiguous nature of the ending might count as well.