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.
I was getting pretty sick of the chicken chaser bs until I was doing battle with town guards for shits and giggles. I parried an attack and the game loaded a different zone and auto-saved over my file. There was no way to go back because manual saving and loading were not a feature of the game. It completely ruined the whole thing and I never returned.
I liked Oblivion but I loved Morrowind. The ui and controls were substandard but the atmosphere and pacing of that game were amazing. Oblivion was Bethesda’s turn to mainstream and love for money.