Ghost in the Shell: Standalone Complex on PS2.
I loved the first Ghost in the Shell game on the original Playstation, and was skeptical of SAC until I played a demo. I was instantly hooked, bought the game within a week, only to return the damn thing the next day. Let me explain:
The coolest part about Standalone is the ability to hack into an enemy and take over their body. This meant, ideally and as far as the demo was concerned, you could apporoach the game as either a shooter or a stealth game. It was great, you could hack an enemy and make him take down his buddies or run interference while you made it toward the goal. Sadly, this open-ended mechanic was not in the full game. You could still hack enemies, but only certain ones, only for a limited time (sometimes as short as three seconds), and often only for one specific purpose (like opening a door or taking out a sniper). Basically, the very thing that would otherwise have allowed the game to be an immersive and open-ended expereince actually made the game all the more linear and restrictive. It's the epitome of bad game design. X-Play gave the game 2 out of 5 and I was nearly ready to send an e-mail right then and there telling them that I'm a Ghost in the Shell fan and yet I thought their review was far too generous and should have been relegated to their "real bad games" segment. I never actually wrote that e-mail; I knew they wouldn't listen to me (God love 'em) and the most I could expect was to shock them by being an anime fan WITHOUT a bias favoring the game.