Some people buy these prototypes out of curiosity about where Sparrow Solitaire began, to enjoy little experiments, or to try game types that don’t otherwise exist on Playdate. That’s why I offered them as a bundle, which has made sense to the many buyers and thousands of downloads to date. As an indie developer it feels good that prototypes aren’t wasted, can be enjoyed or experienced by others, and make a little money to enable me to keep doing what I do.
Itch.io is mostly for playable downloads, not source code, and with no mention of code on my page and each file being a .pdx.zip, it’s quite an assumption to think otherwise. The fact you’re here enquiring about licencing shows they’re interesting enough on their own to some degree or other. Best to you, have fun.