After many tests, I believe this is fully playable. But from the options menu, it's pretty obvious that this game should have background music (BGM), and I've heard none of it. Still, sound effects are okay.
The game is available from the developer themselves, so crosstie might change to download from them instead of Big Fish.
Edit: Oops. Spoke too soon. The Demo from the developer runs fine, but since I have not bought anything directly from them, I have no way of testing if the entering the licence key will work. Big Fish remains the easiest IMO.