This is actually a growing fear of mine, and the only plausible way for it to disappoint. And if that's the case, it would run away with the disappointment award.
That said, my answer for confirmed releases is Final Fantasy 7 Remake. I've always loved the PS1-era Final Fantasy games, and FF7 is no exception. I love RPGs, and I especially love breaking FF7 with its junction (edit: Materia ... whoops lol) system and I know this is weird, but I enjoy turn-based and menu-based combat. Every piece of content that I've seen that involves combat from the remake has me sufficiently turned off. I keep looking for something to distill from the news and information we have about the remake, but the actual moment-to-moment gameplay is the not even realm of what I loved about the original game. And don't get me wrong - I GET IT - it's a remake. It's not going to be a 1:1 upscale of the original game that it is pulling its inspiration from. However, I find it difficult to see this fight and get excited:
So it's character action, which I'm already not feeling for a game that I fell in love with as being an RPG. However, let's shift the perspective and say that I am 100% down it being a character action game and that that style excites me. Its ... bad character action? Why is the boss just standing there for half of the fight while the three characters absolutely unload attack after attack after attack, all taking down 0.1% of its health bar? You marry that combat with the fact that it's 1/3 of a game & story and it ends at the moment where the original game truly takes off ... and it's a recipe for potential disappointment. They are investing so much time, effort, and budget into creating this enormous, gorgeous game set in Midgar that there is very legitimate concern the next game will have FFX-style traveling. What's the point of obtaining an airship if you can't explore a world? I don't know. I'm very concerned with how the final product will look. As for the actual game ...
The character models are gorgeous. The set pieces are bringing the original game to life beautifully. It's fully voice-acted and it is extremely detailed. The music is banging at all times. There's so much to love about what we've seen from an assets perspective, but I still worry about the game. FF7 means more to me than just the assets. I hope they can make the game a worthwhile endeavor that a good game once you crack through the layers of FF7 nostalgia & assets.