My biggest frustration with the game is squarely focused on the checkpoint placement. The game's levels, battles in particular, are generally broken into nice bite sized chunks/section. Before each section there is also, normally, Sun Stone available in some quantity so that in a worse case scenario you can Super Move your way through a section after repeating it multiple times. The current checkpoint system, however, does not line up with those bite sized chunks (at least on normal difficulty). Which means on more than a few occasions I've found myself going through 3 or 4 battle sections repeatedly just to get a chance to try again on a proceeding section where I originally died. It's annoying when the lead up sections are fairly easy, and quite frustrating when those previous sections are challenging.
Yep, this is one of the first things I realized when playing the demo. The death penalty may be high if the player needs to backtrack too often.
That's one of the reasons Cerny said this is a difficult game.