The final boss is pissing me off...
I can beat him no problem, it's the damn dancing that is getting on my nerves... Not so much the dancing being difficult, because what a lame game it would be if it wasn't, but it makes you beat him again once you've failed the dance...which is an absolute waste of time. I think it should only do that if you can't continue. This is the only gripe I have with this game, though. I love it.
I can start the FINAL dance section (once he turns back into normal Jack) with full health and still fail. I suck at button callbacks.
These are my opinions.