Like so many of the animated kids’ movies being produced nowadays, this third installment in the “Hotel Transylvania” series is neither especially good nor terribly bad, just an average time-filler for families looking to get out of the summer heat. Youngsters will probably enjoy seeing the familiar characters again, and their parents may be amused by the occasional flash of cleverness and the use (or abuse) of some popular songs in a culminating musical face-off. And everyone can appreciate the colorful animation. But there is nothing special or memorable in this “Summer Vacation.”

The plot hinges on Drac (voiced by Adam Sandler) bemoaning his status as a lonely long-time widower after witnessing a monster wedding; he even surreptitiously goes on a date site. His daughter Mavis (Selena Gomez) decides he needs a vacation, so the whole gang—Marvis’ goofy human hubby Johnny (Andy Samberg) and their son Dennis (Asher Binkoff); Frankenstein (Kevin James) and his wife Eunice (Fran Drescher); the Invisible Man (David Spade); Werewolf Wayne (Steve Buscemi) and his wife Wanda (Molly Shannon), along with their brood, including daughter Winnie (Sadie Sandler), who’s also Dennis’ best friend; Murray the Mummy (Keegan-Michael Key); Drac’s dad Vlad (Mel Brooks); jello-like Blobby (gurgled by writer-director Genndy Tartakovsky); and Dennis’ cantankerous pet puppy Tinkles (Joe Whyte)—goes along.

Drac falls immediately (or, in the movie’s cutesy parlance, “zings”) for Ericka (Kathryn Hahn), the ship’s captain, not knowing that she’s the great-granddaughter of the count’s onetime nemesis Abraham Van Helsing (Jim Gaffigan), who’s still puttering around in a robotic torso. The two of them are intent on killing Drac at long last, using a secret anti-monster weapon they plan to acquire at the cruise’s destination, the lost city of Atlantis. When they get their hands on it, it leads to a massive confrontation—of a music-and-dance sort—in which a Kraken (Joe Jonas) also plays a role. But by that time Ericka’s attitude toward Drac has changed markedly.

“Summer Vacation” starts off with its best bit, a montage set in 1897 depicting a string of the young Abraham’s failed attempts to off the count. The rest of the movie is essentially given over to the Dracula-Ericka business, which frankly is pretty thin gruel, with occasional bright spots in the form of short routines involving the other characters periodically dropped into the mix—so Frankenstein gets sucked into gambling, with unfortunate result, and Wayne and his wife go on a binge after depositing their brood in a kiddie-care room. (But subsequently they disappear for virtually the rest of the movie, conked out by the villains.) Then comes the finale, in which Samberg’s Johnny gets his chance to take center stage.

All this is moderately agreeable, given that Tartakovsky keeps things moving along without too many dead spots and the animation, from the Sony Pictures Animation unit, is stylish if not terribly imaginative. The movie also carries a moral that’s predictable but inoffensive—that, as Dracula intones, we’re all alike, whether humans or monsters, and should treat one another well.

Among the voice cast it’s Sandler and Hahn who carry the brunt of the dialogue, but Gaffigan and Samberg who make the most of their parts. The rest are energetic and engaging, but their opportunities to stand out are very limited, with so many characters jostling for a few seconds of attention. Mark Mothersbaugh’s score adds some genial touches, and the choice of pop tunes in the big finale will tickle some funnybones.

Overall, though, this franchise is getting a bit long in the fangs, and one has to wonder how many more outings Dracula and his pals have in them. Of course, as long as the families keep showing up, Tartakovsky and Sandler will find some way to keep the monsters active. After all, Universal pretty much stayed afloat on the live-action originals for a couple of decades.