In 2-2, you'll encounter your first enemy, a small green monster. These enemies can be defeated by jumping on their heads. The puzzle piece here is guarded by a series of these monsters and requires you to use the rewind mechanic strategically. Jump on the first monster, then quickly rewind time just enough so that the monster reappears but you are still on the platform. Repeat this process to clear a path to the puzzle piece. You might need to jump on a monster, then rewind, then jump on it again to gain enough height or clear a path. This introduces the concept of 're-using' enemies by rewinding their deaths.
