Mega Man Zero 3
As Capcom is wont to do with its endless franchises, this iteration of Mega Man Zero is an evolutionary step forward, tweaking the base mechanics of the game to be more fun, approachable, rewarding, or whatever. New rules for cyber-elves, new suit upgrades, et cetera. And of course the already nonsensical story keeps compounding upon itself into an indecipherable, robotic soap opera. Otherwise it's generally the same.
I found the previous games satisfying, despite some rather unforgiving difficulty. So what's keeping me from giving MMZ3 more of a chance? It is still utterly ignorant of the concept of checkpoints. Sorry Zero, but if you're going to make me replay an entire level when I die at the boss, I just don't have the patience for you anymore. Especially when I can't really expect anything I haven't already seen in your old work.
Aside: MadWorld lacked checkpoints too, but I only died at a boss once in that game. In MMZ3, death is likely.
Progress: Gave Up -- Almost beat one of the first missions