@Accman et al: You will be able to run the demonstration version of this skill just fine with the Windows 10 version of the Alexa app, but you will not be able to upgrade to the full version (assuming that the full version is unlocked via an in-skill purchase). The Windows 10 iteration of Amazon's assistant does not permit one to conduct any in-skill purchases for premium features. I found this out while playing games such as The Dark Citadel, The Vortex, Six Swords, and Escape The Room 2, all of which support premium features. So if you want to play the full release, you'll probably have to do it through your phone's Alexa app, assuming that platform's version allows in-skill purchases. If not, then you can always get an Echo dot pretty cheaply depending on the time of year, as Amazon often offers those devices at tremendous discounts.
Kai