The Lego Batman Movie: 10 Reasons It's Better Than Snyder's Batman
7. The Tone Is Incredibly Consistent
Tone is a major issue in pretty much all of Zack Snyder's movies, and BvS isn't an exception: the serious stuff is super-serious and so the often sudden flashes of comedy ("I thought she was with you" and all of Lex Luthor's hammy eccentricity) create a discomforting mood whiplash.
The Lego Batman Movie knows exactly what it is and delivers thick and fast laughs to that end, while occasionally stopping to indulge in a heartfelt (if fairly simplistic) plot about Bruce Wayne finally accepting a family into his heart and home.
It's not layered on too thick and certainly doesn't detract from the laughs, whereas BvS is a mess of moods and ideas that leaves the audience unsure of how they should really feel.