The Temple of Elemental Evil. Here I was expecting something like Baldur's Gate or Torment and I get a half-baked generic medieval fantasy with very little explanation given for what's going on or why I should care, a sluggish and broken combat system, dull characters, and the kind of overwrought high fantasy dialogue I stopped writing around 8th grade. And the bugs. Oh the bugs.
Yes, I KNOW there's a tabletop version; that's part of what makes this so frustrating. All the lore information was already there, but they couldn't be bothered to put enough of it in to make sense for people who aren't already familiar with it.
Mirror's Edge. I was really hoping for something special with this one. Yeah, first-person platforming usually sucks, as EVERY DAMN FPS has shown us (why do they even put those bits in?!) but maybe they made a game with great flow and tight controls, where the freerunning and combat blend seamlessly together, checkpoints are placed reasonably, and the visuals aren't blinding bloom or utter darkness with little in between.
Maybe they made that game, but it fell through a wormhole and got replaced with this Bizarro version. What makes it worse is, once or twice in the course of my playthrough, mostly by accident, I DID see the good version of the game. I did two perfectly timed hurtles, leaped to the next building, planted both feet in the face of an enemy as I landed and stole his gun in the space of a few seconds. It was poetry in motion. An entire game like that could've easily scored my Game of the Year vote. Then I got perforated by the three other enemies who'd been waiting to blast me and returned to a checkpoint I'd passed ten minutes ago, and the other twenty tries didn't go nearly so well, and a sublime moment was forever tarnished.