I found out about Krita a good while ago. Since then it's popped up on Steam, for instance, Krita Gemini.

I'm wondering, for those who know Krita much better, what is the difference between Gemini and Desktop? Is it only the touch features?

Krita on Steam has integration with the steam platform (for instance, for synchronizing brush sets across your steam installs). The tablet/big picture mode part of Krita Gemini isn't really specific to Steam, but I just don't package that in the other Windows installers -- all the code is in the git source code repository and accessible to everyone.