Yeah, the last level is a bit of a doozy, although similar to the one where you learn about Rift sizes and grabbing.
I knew that I had a lot of different controls, and that puzzle games excel with small amounts of mechanics. Grabbing became a less complicated version of jumping on top of boxes to be moved, which proved to be a challenge programming wise with all the different actions that could happen, via recordings.
Although, it proved to be difficult to create unique puzzles without introducing new mechanics. Since of how free form the rift is, many of my level designs didn't make it for how simple they were to break.