Hello from the developer,
My personal purchased Steam Deck arrived today. The "Digital Jigsaw Puzzle" game appears to run without any issues. If you run into issues please send me any feedback.
The default mouse sensitivity appears to be a bit high for the game. However you can manually adjust it in the Steam Deck settings.
Note: An official compatibility from Steam has not been given for the game at the time of this posting. It is up to Steam to determine if the game is deemed fully compatible.
Some images if you are interested:
