Software developers can adopt an ad-based model, donation-ware to keep things afloat, or a shareware/freemium model that charges for extra features. Something to always watch for: Crapware installers.
Gary said it’s “possible to load the shareware version of Doom entirely from USB, without modifying the Alarmo.” And they’ve put the software and instructions for running it on Github ...
My first thought on seeing that Nintendo released a little smart device based on its games was "that's cute, I find nothing objectionable about this," but then I spied the gewgaw's $100 price tag ...