I'm not worried about it, really. Any failing of Stranger Things will be due to the writers not having good ideas. There isn't a technical limitation to writing a second season, such as "Everyone's favorite character is a time traveler who breaks everything so we have to write him into feudal Japan because we don't know what else to do with him. The audience will love that story." As a long-time comic book reader and fan, I saw the problems with Heroes as they sprang up in the first season because I've seen comics fail and fail again using those same ideas. Time traveling does not work in an ensemble cast unless everyone else is also a time traveler. Characters who can steal/take/whatever superpowers only work when they're the villain and that villain needs to die/go away. It has to be the story arc of the series because that power in untenable in a hero. Basically, Heroes was a comic book show that felt like it was written by a person who never read any comic books. Those problems weren't new; all one has to do is look at the raging cluster**** that became the Clairemont X-universe to see why one shouldn't play with time traveling on a whim. It breaks everything. That's why good time traveling stories tend to fall into three categories: 1. The audience follows the time traveler exclusively, which allows the writers to ignore just how ridiculous time traveling is and how it really doesn't work if you think about it too much. Doctor Who is a good example of this type of story. 2. A limited story with a clear conclusion. That way if there are larger, over-arching problems that can't be resolved, you get the hell out and, again, don't let the audience think about it too hard. Looper is a good example of this story. 3. You remove the ability to time travel, using it as a story delivery mechanism but only access it from an outside perspective after that point, a kind of deus ex machina. The Netflix show Travelers works in this fashion. Teleportation barely works in storytelling, much less time travel. Look at Star Trek: they have to write the transporters out of 20%-ish of the episodes because it's so easy for teleportation to break a conventional story. So much atmospheric interference in Star Trek. It's amazing everyone isn't dead because the transporters are so bloody unreliable.