Great job on this! I got stuck on one tricky donut (I'm sure you know the one :P) but I managed to get them all. This is a perfect use for the crank. The swapping mechanic is simple but you came up with a bunch of different ways to use it.
My only real criticism is that targeting a shape is a bit finicky if you are close to 2 objects. My suggestion would be to let the player switch targets with a button, and to maybe show your targeting radius as a circle so it's easier to judge how close you need to be.