Answers to Puzzle 12:
What is puzzle 12? Link Below
Here is the official hidden rule for the Bolt Swap puzzle.
A king has four "activation squares": up-and-to-the-right, right, left, down-and-to-the-left. A king can only move if at least one of its "activation squares" is occupied by another king of the same color.
Minimum moves: 15
(Answers provided by CoreyPlover)