The reason it's a 12 is because yes, it is quite slow and yes, it is subtitled but if your child is mature and appreciates less mainstream, arty stuff then I think it'd be fine. There is a theme of abuse that most don't pick up on and Arete is a beautiful character, who hungers for knowledge. Admittedly there is a section in the middle where (SPOILERS) and Arete seem to be in a contest to see who is most bored. I skipped that part the second and third time I watched it. Other than that, I thought it was incredible and the blend of electronics and magic was truly original.