If Pixar is the Rolls Royce of animation, the Sony Entertainment cartoon unit might be described as the Kia, if not the Yugo. Case in point: “Hotel Transylvania 2,” a depressingly flat attempt to wring a few more dollars out of the premise that drove its mediocre 2012 predecessor.

In the initial installment, Dracula (voiced by Adam Sandler), owner of the titular establishment—a haven for goofy monsters—worked overtime to put the kibosh on a romance between his daughter Mavis (Selena Gomez) and a goofy human backpacker named Jonathan (Andy Samberg). Needless to say, he failed. Now the young couple has a child, sweet-natured Dennis (Asher Blinkoff), and Grandpa Drac is concerned that the kid hasn’t gotten his fangs yet and might—horrors!—take after the human side of the family. When Mavis and Jonathan go off to visit his parents (Nick Offerman and Megan Mullally) in California—with the chance they might decide to move there permanently—grandpa takes the boy, along with Frankenstein (Kevin James), Wolfman Wayne (Steve Buscemi), Invisible Man Griffin (David Spade) and Murray the Mummy (Keegan-Michael Key, replacing CeeLo Green) on a trip to vampire-friendly haunts to nudge his fangs out. (One of them is a huge, crumbling wooden tower from which he’ll simply hurl the kid to encourage him to fly.) But the boy’s true nature will finally be made clear only at his birthday party back at the hotel, attended by people from both sides of the family, including Dracula’s long absent, human-hating dad Vlad (Mel Brooks) and his army of ghoulish gargoyles.

“Hotel” has a few good sight gags-—like a gag featuring Jon Lovitz as “The Phantom of the Opera” at the birthday party–though not nearly as many as you might expect, given the setup, and an occasional witty line of dialogue, as well as some moments of sweetness. But for the most part, it’s surprisingly ineffectual in the humor department. The animation is second-rate, and most of the voice work pretty drab. Sandler, in his second stab at Dracula, barely gets by, and Samberg is irritatingly ebullient, though Gomez brings some balance by underplaying. The secondary cast is, for the most part, wasted—the fault not of performers like Buscemi and James, who can bring tons of personality to their vocal work, but of the writing, which gives them little opportunity to do so. It’s nice to hear the gravelly tones of Brooks toward the close, though.

Unfortunately, that last act of the movie is where it goes completely off the rails. The birthday party turns into a massive confrontation between good monsters and bad monsters (with the human guests squashed in the middle), and while there’s lots of frantic action it comes across as more desperate than amusing. This sort of fracas is a commonplace in today’s mediocre animated movies—the better ones take more imaginative routes. But imagination is in short supply here.

“Hotel Transylvania 2” delivers some standard messages about acceptance of differences and bridging cultural divides. But especially in view of the mayhem of the finale, it all comes across as pretty rote.

So does the entire movie. This is one “Hotel” you’d be wise to scratch off your itinerary.

For the record, the picture is being released in both 2D and 3D formats. This review is based on the 2D version.