Good news, we have a page in Steam now!
It will take some time before the game will become available here, I want it to have more content and be worthy of your money.
The demo will become available as soon as I figure out Steam features integration (achievements, cloud saves and what else).
And it will be free.
Eventually (before the release) the game will be localized to multiple languages, so those who want to enjoy it not in English will be able to.