Who Can Kill a Child?

Exactly What It Says on the Tin, Who Can Kill a Child? (or ¿Quién puede matar a un niño?), aka Island of the Damnedis a 1976 Spanish horror movie about an English couple who visits an island inhabited by Creepy Children--and no one else. Turns out the kids just finished butchering almost every adult on the island, which makes lovebirds Tom (Lewis Flander) and Evilyn (Prunella Ransom), and one or two other survivors, marked for death. To survive, the adults may have to answer the chilling question "who can kill a child?"

Tropes used in Who Can Kill a Child? include:

Anvilicious: It's all but stated outright that the children are getting revenge for decades of atrocities against them, and the documentary footage from the beginning seems to support this charge (if not the kids' actions).
Babies Make Everything Better: Subverted.
Better Than It Sounds: It actually avoids exploiting the subject matter and instead gives it the thoughtfulness it deserves; it's also very scary.
Corruption by a Minor: Of other minors, via hypnotism/telepathy.
Creepy Child: Obvious; especially the ringleader.
Deliberately Cute Child: The children play this card a lot to manipulate adults into letting their guard down.
Enfant Terrible: Many of the children.
Fetus Terrible
Infant Immortality: The entire movie is an exploration of this trope, including a memorable subversion.
It Gets Easier: For Tom.
Moral Event Horizon:
Nothing Is Scarier: Some of the tensest parts of the film come in the beginning, before any kids show up.
Sins of Our Fathers: Inverted.
Space Whale Aesop: Treat children better OR THEY'LL KILL YOU ALL!
Title Drop: One of the survivors uses it when explaining why no one fought back against the kids.
Wouldn't Hurt a Child: Played with.