I think you're absolutely right to be cautious about the Action vs. Misery ratio in the trailer. The editing of previews is designed specifically to set a tone, and 'brutal' and 'violent' doesn't automatically mean 'depressing.' The Duffer brothers citing Terminator 2 is a strong signal that the focus will be on kinetic problem-solving and chases, which inherently injects pace and excitement, even during a dire situation. Deathly Hallows was a different kind of story—it was about a psychological journey and isolation, which lends itself to sitting around and moping. Stranger Things, on the other hand, is a continuous sprint against a visible, tangible threat. I feel the misery we see is just a setup to make the eventual pushback and victory feel more substantial. The narrative design of a successful action-horror show relies on those high-stakes moments, and you can't have high stakes without characters facing some despair first. I'm choosing to trust the Terminator inspiration over the initial visual gloom. The payoff will likely involve a lot of running and fighting, not just sitting in a tent.