Four by Four

Every move must be a capture. Pieces move like chess pieces and any piece can take any other; pawns take diagonally away from you. Each piece can capture twice, shown by the beads circling its base. Leave one piece standing to solve the puzzle. Tap a piece, then tap a glowing square.

Sound: wooden pieces on a wooden board, made in Ableton Live from foley and acoustic samples and rendered; a run of captures climbs a music box scale. On an iPhone, turn silent mode off to hear it.

Thirty puzzles, three to nine pieces. Every one was generated and then solved by brute force, so each has at least one way through; the later ones were picked for having very few.