Vexx
Well it took long enough, but I finally put this travesty to rest.
The final boss, Dark Yabu, is probably one of the most difficult bosses I've ever faced in any game, spread across three phases that each take advantage of all the game's control flaws to put you on the cusp of death. But, despite the incredibly terrible ending (wrapping up the terrible story quite nicely), I do feel some satisfaction in finally proving that I am better than this game.
As I said before, there are a few nice things about the game, like the aforementioned graphical effects. It's clear that at least one person on the team had some bright ideas. For instance, when you select a world to enter from the central "Rift Hub," it becomes fully loaded, such that if you re-enter the same world there is no loading screen (this is made possible partially due to the fact that the hub itself is miniscule and bare). And of course, the game has some touching moments.
In the end, you could make a worse game, if you really tried, but Vexx is a great example of why Acclaim is no longer with us.
Progress: 60 Wraithhearts, beat Yabu