The Lego Batman Movie Review: 6 Ups & 4 Downs
3. Some Gags Are Overplayed
One reason why the humour lacks the same verve as The Lego Movie is that a number of gags are simply drawn out for too long or recalled too many times. For instance, there are a number of "Batman does something slowly and awkwardly" gags (like cooking lobster thermidor in a microwave and taking a slow elevator from the Batcave) that get old fast.
The film also devotes a lot of time to the central relationship between Batman and The Joker, and while the movie entertainingly sends-up the absurd yin-and-yang nature of them being destined to fight forever, it goes back to the well too many times in the end.
Plus, considering the movie is aimed at children more than anyone, the joke probably requires a more adult understanding of the characters over the years to truly appreciate, and so will mostly be lost on them.