itch.io

I removed the demo a while back as I felt like the demo was not providing the best experience.

Itch has a good refund policy and they reach out to me before issuing a refund. So if there is anything I can't help with I'm more than happy to approve it.
Steam has a less than 2 hours played/14 days since purchase refund policy as well. 

If there were to be a demo again, I think I would probably provide the full game on a time limit instead. For example it could be 8 hours, which would allow you to experience the entire app unhindered before you decide to buy.