Personally there are a few games which left me very dissappointed, after hyping myself up for years in certain cases.
Divinity Original Sin: turns out I prefer more streamlined, less packed games (love Pillars of Eternity) and that coop play in a CRPG stresses me out.
Wasteland 2: I actually managed to finish this one but secretly I admit I was hoping for a better Fallout which I didn’t really get. New Vegas did the cowboy theme much better.
INSIDE: while the design was cool, it was just a ton of boring, easy puzzles in comparison to LIMBO, its predecessor.
New World.
Started off as a PvP mmo with a focus on territory control with some survival elements. Not a traditonal mmo to be sure, but definitely an interesting concept.
Turned into a generic themepark PvE mmo but with none on the features one would expect from a modern mmo.
Its gotten better since, but AGS tends to drop the ball just a little more with each update.
I peaced out about 3 months after release, tried it again a year later and even with improvements it still couldn’t snag me. I just found myself longing for the original concept.