Mega Man ZX
I'd been waiting for a chance to borrow this from my roommate for a long while. As the spiritual successor to the Mega Man Zero series, it seemed promising enough: interchangeable forms with different and new abilities, set in the same old blast-and-slash MMZ atmosphere.
Unfortunately, I have to say they really screwed the pooch on this one. I could get over the difficulty curve; the lack of health in the early game, the disproportionate strength of enemies, the long (longer than previous games') stretches of level that had to be repeated every time you died or, Light forbid, got a game over. I could get over the limitations of the ability switching; that you start with nothing, and need to earn each new form by beating bosses, each of which has unique disadvantages - I felt like I always had to choose to sacrifice some vital survivability for the necessary jumping height or underwater agility when switching forms, but again, this was not my main quarrel with the game.
What I couldn't get over was the "overworld" system. In MMZX, every area of the game is interconnected, like your Metroid or your modern Castlevania. But, unlike these, the map does not show the connections, or even the areas. No, what MMZX's map shows is a series of nodes - named as A-1, A-2, A-3, B-1, C-1, et cetera - with lines inbetween them to indicate that they are somehow connected. With any number of places for the doors inbetween nodes to reside, it is functionally impossible to get anywhere. There are also teleporter/elevator "trans servers" to move quickly between certain locations, but they are far too few to be practical.
I don't feel like I played ZX enough to give it an absolute evaluation, but the mechanics were just so bothersome that I felt like the rest of the game wouldn't be worth it. I will keep an eye on the sequel to see if it has fixed the map issue.
Progress: Gave Up -- Got Zx, Hx, Lx, Fx suits