A good show in the end, not a great show. I feel like the show ran straight into what I would term the 'Lost' problem. They were initially building up an interesting mythos and a set of mysteries, but in the final few episodes they basically abandoned any kind of mystery element to tell a very standard monster story. They could have done something interesting with Brenner or the government agency, but in the end he was just a crazy scientist, and they were just fighting communists. They could have done something interesting with the monster, but in the end it was just an animal that eats people. They could have done something interesting with the upside down, Eleven and people's interactions with the dimension, but in the end it was just an evil version of the town. All very regular story tropes, so in the end all the drama came from the human characters and not from the world.
Of course, the flip side to this is that building up, and then satisfyingly concluding a mystery over several TV seasons is extremely difficult as Lost and its many imitators have shown. Stranger Things could have focused more on plot twists and world building, and then several seasons later ended up with mangled garbage explanations for everything that retroactively ruined the entire venture. Further, by wrapping up story threads now, Stranger Things felt like a complete story, rather than simply a prelude to the real story later on. Someone can watch Season 1 only and never watch the rest and still feel entirely satisfied with the ending.
There's not really an ideal solution, a show can either choose the high risk of mystery, or keep things simple but also lessen the interest. I'm always going to prefer the riskier option myself since I've never gone into that kind of show with expectations of a satisfying conclusion and can thus end up with something that meets my expectations or something pleasantly surprising. But I know there are plenty of others who feel differently.
Some will perhaps point out that the show does still maintain some mystery, as they showed with the season 2 hints in the finale. But for me that was the worst part of the ending, as it seemed like the creators wanted to have their cake and eat it too. I can already tell that the worm will end up just another monster, Eleven will return and the government agency will continue to be boring. That's the kind of show they're making, and that's fine, it's still good as I said above, but if they pretend things will be mysterious and it ends up predictable then the show would really suffer.
That's just what I thought.
