I have exhausted my Bing fu looking for any other way to purchase and play this game. Even the Xsyon home page only lists Steam. Is Steam the only option?
You can purchase a Xsyon account directly from the Play Now link above. The first step it to register a forum account, which is required for all players (direct and Steam). Once you've signed up, there is a purchase link.
Thank you, I somehow overlooked that, I purchased game/1 month, then spent the next 6 hours exploring/tinkering/figuring out things. Very interesting.