In this inevitable sequel, helpfully subtitled “The Second Part,” the heroes of Bricksburg — Emmet (Chris Pratt), Lucy (Elizabeth Banks) and Batman (Will Arnett) — get back together, this time to defend their planet against a Duplo invasion. I don’t know what that means. Initially, the madness seems a bit scattershot, with multiple subplots and tangents. But the puns and one-liners keep you amused until the surprise denouement comes along to quite satisfyingly tie everything together. Like the first, this all-ages movie is shrewdly and enjoyably self-referential and arguably insane, while it slyly delivers a good message for kids. Topping it off is a catchy soundtrack that includes an especially invasive earworm titled “Catchy Song.” As good as the first? That’s a high bar. Close, though. (107 min)