You are buying the current version of Pyxel Edit, and will get access to any future versions without paying anything extra. It is developed by one developer (me), and while I'm determined to make the application as good and complete as possible there is no guarantee that it will be completed, hence the lower price.By purchasing a licence you may use the application on computers owned by you. You may not distribute it, or your key, to anyone else.Pyxel Edit is currently in beta and most likely has bugs and errors. I do not take responsibility for any damage or losses (including but not limited to loss of time, work, sanity...) caused by the use of the application.If you have any questions please send a message to firstname.lastname@example.org.I hope you will find Pyxel Edit useful!
Although this doesn't really answer what you're asking, plenty of users are or have been using PyxelEdit for distributed games already. I've never heard Danik say anything in regard to License specifications though. How I understand the terms: You buy the software, so you are free you use all your art in any of your games.