One thing that confuses me slightly. People who love GB2 (or at least like it) as I do, turning around and bashing this movie for its comedy style when GB2's comedy style was SO unlike the original that it can take you out of the movie if you're not ready for it.
GB2 is louder, it's flashier, it has actual written jokes and gags that aren't deadpan improv like a good bit of Murray in the original GB.
It has what you could essentially call skits in it. In every way, it is a modern movie but with whatever pop culture humor was the style of the time.
It's pretty much the exact same style of movie, based on the trailer of GB16. At least in my view.
I think the biggest problem that most people have with Ghostbusters 2 is that it is almost a beat for beat remake of the first movie. The movie follows the same story structure and even places many of the same characters in the same situations. It doesn't quite stand up on its own without aping the original movie. But with that said, it still did have some original ideas with the mood slime concept, the New Years/ end of the '80s story line and the concentrated bitterness of the entire City of New York, which was kinda a real thing in the '80s.
The characters are reintroduced in reverse with Winston being the first Ghostbuster to appear into the movie. I did also like the "where are they now" segment at the beginning with Peter being a talk show host and Egon doing his weird ass science experiments. I kinda wish there was more of that, but I feel like those elements were dropped so quickly and forgotten. The villain wasn't bad and Janosz had his moments. But the movie wasn't as character driven as what it could have been. The first one did this so much better. The ending was a little too abrupt as well.
As for the humor in the first movie, outside of Bill Murray's improvised comedy, it was pretty well scripted. I think Bill Murray was the only one that was really allowed to go off the rails while everyone else stayed close to the script. In Ghostbusters II, you can tell that Murray didn't really want to be there, think about how many times he wasn't suited up as a Ghostbuster. I could only imagine that they were betting that he would perform his magic like in the first movie, but he wasn't really there playing ball with them.
Ghostbusters 1 did have a less structured comedic style though, with less set up and pay off jokes. But I felt that this also helped create a believable world. Also, the characters didn't have any recognizable story arcs, which made them feel a little more grounded to me as well.
They were also playing up a little more to the cartoon series, with Janine being more like her cartoon character and there was a bit of a forced love story with Luis Tully... though I did find that element to be amusing anyway. Slimer was originally planned to have a more prominent role in Ghostbusters 2 and there was a whole subplot that was cut out of the movie that features Luis Tully trying to capture Slimer in the firehouse, he later gives up and befriends the ghost:
https://www.youtube.com/watch?v=Y7UnFx6OLVs . This leads into the scene with Slimer driving a Bus with Louis responding with "you again?" .
To be honest, GB2 is not a terrible movie, but it does live under the shadow of the original. If you are in the mood for more Ghostbusters, I would still recommend it, I suppose.
