You can use this tileset for whatever you like (CC-0).
Credit is not necessary, but if you create something using this tileset I'd be happy to see your work (you can comment with a link).
That being said, you can still credit me if you feel like :)
Since there were questions, let me clarify:
- you can use this tileset in both private and commercial projects
- you can modify this tileset
- you can distribute both modified and original work
- you are not required to credit me, (although I'll appreciate if you do)
- you are not required to post a link to your work to me, (although I'll appreciate if you do)