mercenaries 2 - broke the formula that made the game a stellar hit. the needless resource gathering for oil. waiting too long to get a hook, broken controls on vehicles, buggy co-op (could have been a killer feature if done right) ... also needed more sams something to counter balance helicopters.

also why could you not reset the game back to all factions playing after beating it like mercs1 or crackdown

(co-op like crackdown 1 or 2 or gta would be fine)

edited.....

the most recent hitman.... to linear  … and quicktime events… really was almost the opposite of what hitman games are supposed to be. 

crackdown 2 .... the changing cars were gone... and the story/ variation sucked compared ot crackdown 1... still fun to play though

FF XIII/XIII-2/XIII-3
GTA IV
Lair

I would have to say The Walking Dead game. The one by Telltale not Activision. I mean it had a very good story but damn was the gameplay boring. It was getting so much praise from reviewers and it sold very well so I thought I should check it out. I like the fact that you get to make decisions that affect your game, but the gameplay itself was very simplistic. I've wanted to go back to play the game again to choose different choices to see the outcomes but I can't convince myself to play through it lol.

Hard to choose. Metroid: Other M perhaps, but there are other solid candidates such as...
Crackdown 2
Golden Sun: Dark Dawn
The Conduit
Prince of Persia

Next-gen also has serious disappointment potential.

Final Fantasy XIII is very popular here....XDDD. I agree that FF XIII was somewhat dissapointing, but because it have the "final fantasy" name on it. It's not a bad game, but it's not the AAA game that everyone expected, including me. Bioshock Infinite and Skyrim are the same to me. Like FF XIII, they are very good in most ways but have something very wrong.

But to me, the most dissapointing game, the one that I didn't have too much fun despite the good scores everywhere was LittleBigPlanet. So many content, so many creativity from some users, but I coudn't enjoy the gameplay and physics of sackboy, it didn't feel intuitive to me.

MP3 Corruption

it felt lifeless boring endless corridors bad broken bosses.

The choices don't affect much really :/ characters say some different minor things but it's still the same ending and story afterwards. They might matter for episode 2, so there's that i guess.

haze is the only game I can think of. I remember being so hyped for that game,only to force myself to beat it in a few days and trade it in. It's the only time I felt that I truly wasted my money.

Call of Duty and Halo series and their countless wannabes and clones of these two generic popular series are a plague that never goes away. Shooter games rely on the same no strategy game play. Online the cheats/glitches, faster cable connection and the fastest reflexes wins most online matches. Call of Duty and Halo rely on recycling the same old game and adding a staggering one or two small additions to the next version for a mind blowing $60 per game. If you have played one Halo or Call of Duty game you have literally played every single one of those games in that franchise or wannabe clone of these game series.

Metroid Other M

What could have been an awesome fusion of old school Metroid and new school action gaming was butchered by a multitude of awful design decisions, from clunky controls to a cringe-worthy (and worse, unskippable) story.

Resident Evil 5

From the greatest game ever made to a hollow, mediocre shooter without an ounce of fear or cleverness. Crushing letdown.

I wasn't disappointed by GTA4 because based on previous GTAs I expected it to bore me, which it did