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.
Torment: Tides of Numenera
But I think I’m mostly disappointed in myself for not sticking with it. I joined the kickstarter, followed all the updates and was genuinely excited to explore the world being described.
When it finally came out I only played it for a few hours before losing all interest in it. Too much text and everyone seemed to have their life story to tell. Which is odd, because usually I love text heavy games with tons of lore.
Every so often I tell myself to give it a second chance, but never seem to be able to muster the energy to follow through.