I should just say up front that I thought “The Lego Movie 2: The Second Part” was great, and I don’t know why I’m surprised.

I’m not, really, but once again this series has surpassed expectations. We all thought a movie based on a series of plastic building bricks was basically a crass sales ploy, but what it actually turned out to be was a brilliant, emotional and hilarious sales ploy. So, good for them.

“The Lego Movie 2” starts immediately upon the end of the first film, where, in the real world, our young hero learned that his sister was going to be allowed to play in their father’s Lego utopia as well, and in the Lego world, an invasion of lovably destructive Duplo blocks was just beginning. That turned out to beginning of the end for MegaCity (or whatever that huge Lego collection was called).

Flash forward five years and what’s left is a desolate wasteland. Bearing a distinct “Mad Max” vibe, the remaining Lego characters eke out an existence in this dog-eat dog world, with the fear that anything new or shiny would be detected by the Duplo aliens and immediately destroyed.

It’s a rough life, but one that Emmet, the eternally cheerful hero of the first film, seems oblivious to. Though best friend Wyldstyle, aka Lucy, has done her best to toughen him up, it seems as though this little Lego is destined to always see the good in everyone.

That all changes, however, with the arrival of General Mayhem, representative of the Sistar System — the home of an alien race whose queen wishes to marry none other than Batman. Emmet watches as all his friends are kidnapped and whooshed away, leaving him to rescue them.

But along the way, he finds a new friend, Rex Dangervest, a raptor-training cowboy archaeologist who has some pretty definite ideas about what to do about the Sistar System.

In many ways, this is a typical sequel — you get more of the same, but a little bigger. Yes, there are more songs, more fabulous building sequences, and more interaction with the human world. But this film has a completely different theme than the first did.

This story deals more with how to get along with others and to look past our own prejudices and preconceived notions. The writing is typically sharp, retaining writers Phil Lord and Christopher Miller for the script, if not the director’s chair. Returning cast members Chris Pratt and Elizabeth Banks are great, as is Will Arnett’s Batman, which seems like it would be such a blast to play.

In addition, the film features Stephanie Beatriz as General Mayhem and Tiffany Haddish as Queen WatevraWa’Nabi, a bizarre shapeshifting creature whose song about NOT being evil is the funniest in the whole film… that is until the credits. Make sure you stay for a brilliant Lego sequence that I could swear is done with real bricks, and a great song from The Lonely Island all about how great the credits are.

Finally, it was great seeing Maya Rudolph as mom. She’s doing great work lately, from small roles in feature films to a recurring and hilarious part on “The Good Place.”

No, this film doesn’t break a lot of new ground, but it’s different enough to be memorable, and very sweet and funny. I’d say it’s not quite as good as the original, and a little better than either “Lego Batman” or “Ninjago.”

Actually, one of my only real problems with the film was that the volume seemed like it was a little low for a good part of the movie. That could have been an issue with the theater, though, so it’s hard to tell. All in all, this is a great movie to take the whole family to, and sweetly funny enough to be your Valentine’s date night. Grade: A-

“The Lego Movie 2” is rated PG for mild rude humor and toy violence.

• By CHRIS JENNESS