I haven't seen a Shrek movie since Shrek 2, and I'd say this was about on par with that film - not terribly original (three horror movie parodies wrapped in a Simpsons "Treehouse of Horror"-style format), but still decently funny. Nothing to bring the house down, though it had its moments. For instance, the revelation that Jiminy Cricket was the "evil spirit" possessing Pinocchio made me chuckle, and I did enjoy Donkey and Puss In Boots trying to one-up each other while telling their story. In fact, I'd say that segment was the best one, since it felt a lot more character-driven and the jokes came faster.
In short, not something I'd seek to watch again, but an okay time filler. Basically what I've come to expect from DreamWorks in general.