I think the best way to review this show is to review it season by season.

Season 1: a very good and spooky season, brilliant premise that is played to perfection. Very mysterious and atmospheric. 9/10

Season 2: a lame retelling of a similar story. The plot with Will being possessed is interesting but the mind flayer is bland and boring. All the Demi dogs are fun until you realize that they've already fought a Demogorgon so why should we be scared of the mini ones. The emo eleven subplot is one of the worst things I've ever seen. So it's really just season 1 but with all of its good qualities sucked out of it, it's boring, the characters are dull and so is the plot. 3/10

Season 3: season 3 really is an outlier, it's not dark, gritty, and atmospheric. It's goofy, colorful, and comedic. This makes it feel like a complete tonal whiplash Compared to the others. And since it is a comedy any attempt at tension or horror fails. The one good thing is that it does develop max's character, that's it. 4/10

Season 4: by far the scariest, grittiest, goriest, and creepiest. All while still being pretty funny. As much as I do love this season it does have some flaws. The entire bullying subplot is the worst thing since emo eleven. The final battle between eleven and verbs is terrible, but the worst thing is that the show doesn't seem to have the will to kill off primary characters, which it sorely needs, they think that if they kill of one of these "beloved characters" then the show will suffer. It WON'T you need to kill off characters to keep the tension, and characters introduced in that same season are not main characters. 8/10.