My expectations were severely lowered for FF XIII after the disappointment that was FF X; thus, I wasn't surprised when it turned out rubbish. XIII-2 managed to help me forgive XIII a bit more too.
Off the top of my head, here are some games that I would add to my own "extremely disappointing" list:
- SSX On Tour
- WipEout Fusion
- Final Fantasy X
- Super Smash Bros. Brawl
- Spyro: Enter the Dragonfly
- Crash Bandicoot: The Wrath of Cortex
- Command & Conquer 3: Tiberium Wars
- Ico
- Monster Hunter Tri
All of these games I had some level of expectation which they managed to vastly under-shoot.







