The movie bases the story thoroughly on Lego, and many movie funny parts are based on Lego characters.
Its funny points could be checked here in this page.
Alfred Pennyworth: Were you looking at the old family pictures again?
Batman: No, I wasn't!
Alfred Pennyworth: Sir, I have seen you go through similar phases in 2016 and 2012 and 2008 and 2005 and 1997 and 1995 and 1992 and 1989 and that weird one in 1966.
Batman: I have aged phenomenally
Batman: Black. All important movies start with a black screen. And music. Edgy, scary music that would make a parent or studio executive nervous. And logos. Really long and dramatic logos. Warner Bros. Why not Warner Brothers? I dunno. DC. The house that Batman built. Yeah, what Superman? Come at me bro. I'm your kryptonite. Hmm, not sure what RatPac does but that logo is macho. I dig it. Okay, get yourself ready for some... reading. If you wanna make the world a better place, take a look at yourself and make a change. Hoooo. No, I said that. Batman is very wise. I also have huge pecs and a nine pack. Yeah, I've got an extra ab. Now lets start the movie.
Joker: You complete me.
Computer: What's the password?
Batman: Iron Man sucks.
THE LEGO BATMAN MOVIE Extended Clip - Villains vs Batman (2017) Animated Comedy Movie HD:
Director: Chris McKay
Voices: Will Arnett, Michael Cera, Rosario Dawson, Ralph Fiennes, Siri, Zach Galifianakis