I tell you what wood have helped greatly with this last puzzle, an option to chance the background to white. The ground and sky color were slightly different but there wasn't enough contrast with any of the color options to pick them out. I had to wait until I had formed some white space up top to be able to drag groups of pieces on top of it to be able to re sort them.
That wood be really neat. Maybe it could be done without much storage required if it saved replays something like how Doom did.