These LEGO movies, guys.

I absolutely adore the original LEGO movie. It's a very nearly perfect piece of art. Great story, well-written, brilliant self-aware humor, and a very touching and healthy message.
So, naturally, I was thrilled about the prospect of more LEGO movies!
I think the best thing about the LEGO Batman movie is that it pokes fun not only at itself, but all the previous reiterations of Batman and several other DC Universe movies. There have been plenty of serious incarnations of Batman, so to have one that acknowledges all the previous ones and doesn't mind making fun of its own franchise is a welcome fresh take.
However, for that reason, I do think this movie will be less timeless than the original LEGO movie. The original LEGO movie, while it had cultural references, didn't depend on them; it was an original story with a very classic message. LEGO Batman depends on knowledge of the franchise, and is a bit more of a cliched, on-the-nose story (although still a sweet one). It's more of a throwaway, fun flick. Definitely something I'd watch again, definitely something I enjoyed, but not a new classic.