Ryujin
Legend
It's generally the telling of the story, not the story itself, that makes a good movie. You can have a very straight forward and simple story that, told well, catches real public interest. Think about "The Fifth Element." There really isn't a lot of story there and the resolution is, "Love is the strongest force in the universe." Taken straight-up that's pablum for the mind, however, the style, imagery, and action carry that simple and bland story to some pretty big heights.Right, I think it works as a stranger things derivative, but the fan service didn't really add anything to the experience, IMO. So, not only is the movie unoriginal in theme and tone, but it doesn't do anything interesting with what came before either. It's a mediocre story, but with a good cast and execution.
If the supposed lesson here is that sticking with canon is the successful method, I'm afraid its the wrong lesson. It's just going to encourage more unoriginal sequels and attempts going forward.
I was fine with Egon being the ghost and the callbacks to an incident in New York that no one remembers, but should. Maybe they should have tossed in a throw-away line about no one really being able to hang onto memories of real supernatural events, but it was fine as it was. Maybe show Egon in silhouette during the final battle, as he's going off to his rest? Something smaller than what we got. It's still a fine movie but let down by the last act by being too.... much.