Yep! you read that right! There is a playable demo of Puzzled you can try out! Just go to files and you will see it!
It is a short demo, and yeah there aren't any puzzles. you could say it's a preview. But this opens a good door for playtesters, like BionicCoyote!
If you experience any bugs or glitches (that I could or could not fix due to source engine personal problems) got to Forums and post in the Bugs section.
If you for some reason want to make some custom map for it, go into Forums again then into the Maps section and put a [DEMO] label in the title.