Passable.
I think I wanted more from 'Immaculate', though what's provided is fairly watchable to be honest. Visually it looks neat, too. Sydney Sweeney's performance is as good as expected, the rest of the cast are all competent; Álvaro Morte the standout of them.
The run time does fly by, I kinda felt watching that there wasn't really a middle - just one long build-up to the main event at the end. Speaking of which, 'the' scene at the conclusion made me smirk, the problem is that it most certainly was not supposed to; Cecilia's screams immediately sounded like that "best cry ever" meme* to me, I couldn't help but smile, I'm sorry.
*never knew the backstory to that clip until searching for it here, it's not quite so amusing now to be honest. awks.
All in all, I'd narrowly class this as a film worth watching. I almost got to see it by myself in an empty cinema, though a group of two inexplicably arrived like 30-45 minutes into the 90 minutes! That's gotta hurt.