This level features a green-glowing enemy that moves back and forth on a platform. The puzzle piece is above this enemy. To get it, you need to jump on the enemy's head. However, if you miss, the enemy will continue its path, and you'll have to wait for it to return. The solution is to jump on the enemy, then immediately rewind time. Your jump will be undone, but the enemy will continue its movement. This allows you to repeatedly jump on the enemy's head to gain height without having to wait for it to reset its position. This is a classic example of using your rewind to 'farm' height from a time-immune enemy.
