I've continued working on the game, and have published a small update.
You can now click a button to bring loose puzzle pieces to the top.
The button appears in the main puzzle game, with this icon: ⇅
This should make it easier to find single pieces when we have almost finished completing a puzzle.
It's a new feature and I have tested it myself, but I'm interested to hear that it works well for everyone.
I have also published new DLC content. Check out Fantasy Jigsaw Puzzles - Deserts.