I finally saw this, and I was fairly entertained. The barely-supervised kids in the audience seemed to enjoy it, they were really excited whenever "Igor" interacted with the living. I liked how it set up Egon's plan and slowly brought it back into focus over the course of the film, though I don't think it justified the shambles he made of his relationships. I was waiting for a payoff to that, a justification for why Egon became a weird jerk and everyone doubted him, but it never really came. His relationships were repaired with a CGI cameo that went on far too long. I liked Phoebe and Podcast. The Walmart scene was pretty blatant marketing, but Walmart is a fact of life in small towns. It's not all mom and pop general stores and carhops.
Gozer didn't make any sense. In the original story, Shandor thought society was too sick to survive so he founded a cult to raise the Destructor. A gate into another dimension opens, Gozer's there on its ziggurat, and a human chooses Gozer's new form, whether that's a sloar or a marshmallow. Egon figured out the interdimensional gateway goes both ways, they crossed the streams and directed the total protonic reversal into Gozer's domain. The gate was destroyed, Gozer's physical form collapsed, and the terror dogs reverted into humans.
This time, Shandor comes back to life and wants to rule the world with Gozer? And Gozer kills him then lounges on a couch waiting for ... sacrifices? But they lure it into the trap field by trapping a terror dog, even though Gozer doesn't need the Keymaster and the Gatekeeper once the gate is open. Then the old guys try to do the total protonic reversal trick again, but without an interdimensional gateway the explosion will kill everyone there. Which is fine, they're trying to kill a god, some sort of sacrifice is usually required, but there's no gravity to this decision. And there's an awful shot where Phoebe and Gozer do the lightning/proton stream battle. Did Gozer forget it's a nonmaterial spirit and can simply disappear? That's literally what it did when the Ghostbusters shot at it in 1984.
Finally, why wasn't the drunk mom covered in ectoplasm after she hugged her dead dad?