Amazon Prime has The Changeover available for rent or purchase.
You may or may not be familiar with Margaret Mahy, but she's probably New Zealand's most beloved author, and I read The Changeover as an adolescent and absolutely loved it. The movie really does it justice. The casting is amazing, and the film unpacks a lot of the theme of transitioning into mystical power as a transition into adulthood thing. The film is eerie and creepy and suspenseful without being gory, and has a sort of starkness to it that is interesting rather than bland.
Seriously though, is there any media where Timothy Spall isn't a fucking creeper? He's downright scary in this.