I watched the original before I went to see the new adaptation. I wanted to be able to accurately judge if the plot was mirrored.
For the most part, the movie is original. Yes, it starts with the scientists being kicked out of their respective universities, but it’s for different reasons than in the original. The appearance of ghosts is actually given a new reason, no god trying to return. Instead, it’s a regular disgruntled man who is setting traps to power the ghosts. (If you stay until after the credits finish, there is a scene that mentions Zuul. So perhaps he will appear in the sequel.)
Aside from the obvious roles of Kevin and Patty, its hard to know who each of the three professors the women are supposed to represent. I’m sure this was done intentionally, and I’ll admit, even Kevin and Patty are radically different than their counterparts in the original.
Actors and actresses from the original film, do make small cameos in the new film, which is a nice bonus. There’s a few other items from the original movie, like the firehouse, hearse, and even Mr. Stay-Puft—but all with a new twist.
If you can, I’d suggest seeing the movie in an IMAX. The fight scene at the end of the film would have been great to view in an IMAX. I didn’t have one close, but wish I’d made the trip. It would have been worth it.
All in all, yes, a great movie. You’ll find yourself chuckling along, whether you are fan of the original or not. Don’t let the fact this is a remake deter you, it’s highly original and does a good job of staying respectful to the original film.