This review failed to mention a few things that I think are important.
1) The story structure is cribbed from the original Ghostbusters almost beat for beat. It almost certainly does not "do it's own thing" and it will be more apparent if you are very familiar with the original movie and you will not be able to help but compare them and it's not a favorable comparison.
2) Kristen Wiig went to the Michael Cera school of acting. She is Kristen Wiig playing Kristen Wiig's character.
3) Mellisa McCarthy is also playing Mellisa McCarthy. Expect: Unfunny improvisation about her wonton soup.
4) Plot holes you can drive a truck through. It's hard to describe this without giving spoilers, but let's just say there are several set-ups in the beginning of the movie that do not pay off and the primary theme, or plot between Wiig and McCarthy is entirely ignored until the final act, which is then sent to a rushed conclusion almost as if, "Oh yeah, that's supposed to be the character development - QUICK DO SOMETHING!"
5) Extremely distracting product placement. This seriously needs to be mentioned in every review. I felt like I was watching a feature length commercial at some point.
In my opinion this movie is Pixels with worse CGI and if it had starred Adam Sandler probably would have gotten universally negative reviews instead of the mostly "mediocre" reviews it got. What does that mean? Simple: I think people grade Sandler's movies harsher than they should and I think they graded this movie gentler than they should. I'll leave reasons for that up to other people to ponder - I've got no interest in it other than observing it.
The only final thing I would have to say is that if you are sensitive about the entire marketing campaign around this movie, then you will probably notice that there is a cringeworthy theme of both a) insulting stereotypical "nerds" and b) insulting men in general. Quite clearly in several places Rowan is used as a stand in for what Paul Feig considers his internet detractors and on the later topic you can do a quick audit yourself and come up with the calculus that every man in the movie is either stupid, a jerk, or evil (an outright villain). I wouldn't take my daughter to see this movie because of this stereotyping any more than I would encourage my son to see all women as over emotional, dependent bimbos.
I can't help but think this is part Paul Feig's natural pathos (he seems to be acting out) and one part response to the internet detractors of the movie, but in the end all I can say is "Good job Paul Feig, you turned the one thing that I thought might be a positive about your movie and turned it toxic."