Note: The following contains spoilers.
There’s nothing wrong with slasher movies being sort of light on plot. Halloween is one of the greatest films of all time, and it doesn’t have particularly deep characters with complicated back stories, yet the film still works and then some. However, “conventional” wisdom would tell you that if a slasher was good with little-to-no plot, adding some plot would only make it even better. But, of course, that isn’t how movies actually work.
There are some things to like in Zombeavers. It’s a goofy premise with a few memorable characters and a real “the hell with it” attitude that lets you roll with its ridiculous premise and off-the-cuff characters. But the movie gets too plotty when it comes to the love triangle that kicks the whole plot off. Neither Mary nor Sam nor Jenn are interesting enough characters to make us really care about their lives, so the amount of time spent on the cheating story feels like a lot of build up for barely any payoff. The end of this plotline is when Jenn burst through the floor to bite off Sam’s dick, which could feel like a powerful moment if we had reason to feel bad that Jenn got cheated on, but she spends the entirety of the film moping, so instead we’re just kinda happy that a character who has spent the entire film annoying us got his junk bitten off.