In the 8th level, toward the end, there is an octopus puzzle. Solve it to rescue the trapped cave woman and unlock this achievement:
The goal is to move him to the other purple spot in front of the woman on the right. The tentacles are directional buttons. However you cannot go in the same direction 2 moves in a row.
R, U, R, L, U, L, R, U, R, U, D, R, D, R, D.
The octopus will grab the girl and flip his tentacles. They now point in the direction they go, instead of corresponding to a directional pad.
L, U, R, L, U, L, U, D, L, D, L, R, D, R, L, D, L.
The octopus will drop the girl off. Pick her up and go left to unlock an achievement.