Well it actually blew pretty much as badly as the first two films or more precisely, as much as Attack of The Clones. All acting is entirely wooden, which makes Anakins plight and catastrophic choices completely unbelievable. No horror there. Obviously, slaying of little children always works - but really, even the gruesome fate of the Jedi comes off empty.
The film could easily have been 30 minutes shorter. Just eliminate all the wooden acting. It does little to no good.