So I never actually saw Casshern, since it had already earned itself a rep as utterly incoherent shit by the time it actually came out. Goemon has an even worse rep -- even people who liked Casshern are getting their hate on.
But hey, the trailers were insane.
Goemon is by no means a good movie. It is awesomely terrible in the Southland Tales sense. At least, for about half the length. I absolutely loved the first half -- filled with batshit crazy people doing batshit crazy things on batshit crazy sets surrounded by batshit awful special effects, it gloried in matte paintings and hilariously overstylized CG. The first act ninja fight alone is totally one of the greatest ninja-riffic things ever filmed.
It sort of implodes on itself in the second half. It sort of loses sight of a few key things.
A. Ninja DO NOT CRY.
B. Since you've established that ninja can leap a hundred feet in the air WHENEVER THEY WANT then it logically follows that: Ninja do not have problems getting through crowds.
I am aware that Japan is the land where melodrama will never fucking die, but wisecracking ninja doing crazy shit worked a good deal better than crying ninja having sad things happen to them, and when that gave way to five successively worse endings it sort of stopped being hilarious that everyone was wearing Western armor or fucking Stormtrooper outfits and posing dramatically in front of sudden solar eclipses and just got weirdly dull.