Braid, Anniversary Edition

Most puzzle pieces in this world are relatively easy to get. There are two, however, in 2-2, that you can't get until you get the puzzle piece in 2-4, then return to 2-2. It's pretty tricky considering it's the only place in the entire game where you can't get a puzzle piece until you progress farther.

Below is a video walkthrough of all puzzle pieces in World 2, in case you get stuck on any. Full credit to the creator.