yeah, hard to say. she says the lacked the key.. a tuning fork. but, they did have tuning forks.. and she also implies the fork was used to tune into the right frequency.. which, they did dial the right dimension...
I'm not sure any of that made much sense. some other more likely stuff, is "the demon is lonely". so presumably the door was only one way. The difference being her door was both ways. also, since it was an artificial comet, perhaps the demon simply wasn't ready for the door to open.
theres a few other ways I would have liked to see the ending go. like, that no longer being Melody. 20 years in a demon dimension. that would have been the demon just pretending to be her. That could have been the demon meat puppeting her. That could have been her totally corrupted into a loyal wife/slave of the demon.
what happened to Iris Vos? like here, she shows up in the gate, when opened the second time. why? was she in league with the demon at this point? controlled? why would the demon have let her near the doorway? she wasn't pregnant and didn't have kids? so it didn't give her, her wish. did I miss something with her? why wasn't she still in there, the third time?
Did "archive 81" ever get explained? was it just supposed to be the name of the tapes being auctioned? I think the title hurt this.
I would kindof like to see more movies/tv take this from the other side. like, midnight mass kindof does it the same. they touch upon the cultists backstories. but don't REALLY dive into it, in the way they should. Think about it. imagine if you came across some supernatural being, or event. something undeniably real. atheisms is wrong. Christianity is wrong. not many films really explore someone finding the truth like this. platos cave. from the point of view of the new cultist. They don't even have to be an entity with enmity.
like, Apostle and the druid/forest god. The druid was not evil, the cultists fucked it up. The Ritual from the villagers perspective. the god testing people. forcing them to face their traumas. Starry eyes kindof does this, with evil outcome.