I have seen the play and the only part of the supernatural that anyone saw all died in the Creel house or were explained away as the ravings of a lunatic and finally covered up by the staff at Hawkins.

The only thing Hopper, Joyce and Bob Newbie saw were mutilated animals and unexplained radio noise, that all the adults explained away as a coyote.

Part of the Broadway play is a high school play that Joyce directed, while as a new kid Henry was in the play most of his interactions were with Bob Newbies Sister who ran away from home at the end of the play. Newbie’s Sister and Henry kept their romance a secret from everyone because her father did not want her dating.

To all the adults that you know from the TV show Hawkins was just a boring little town and pretty much everything that happened in the broadway play happened to characters who died or where part of the lab.

The play is an incredible experience and really does a great job of threading the needle of the show’s story. The play talked about what went on in that cave as for the reason the Creel family moved to Hawkins, but it really had Dr. Brenner moving things to make that happen.

As far as the life in the Abyss, the planet sure looked dead to me and I thought it was pretty clear that the kids were being used to reanimated the mindflayer. Something killed everything there.