I'm actually looking forward to this game's difficulty. Having beaten GTI in just 4 days with minimal grinding and only fainting once or twice (I know of one instance in Tyrian Maze), I think this will keep me playing for far longer, even if I'm not going to go for 100% (which I plan on going for).
Yeah, the biggest spot of trouble I had was the Munna bossfight prior to Kyurem. I kept getting wiped out until I found a passcode for All-Protect Orbs. I popped one--just one--and the bossfight went from murderous to a complete joke. Kyurem was also laughable with super-high-level Dual Chop, and even the uncrackable Bitterfrost was crushed into snow cones by my withering barrage of blades.
...Great, now I'm hungry for a snow cone. *facepalms*