Hi @Mausakrobat28!
Yes, this is a demo.
Our plan is for the game to be always free.
We are supported by our community on Patreon and Subscribestar.
There you can influence the visuals and other parts of the game with your votes and receive game build prior to public release - among other things.
Every Friday we share a dev log and we have a community poll (free to participate), and every Tuesday we post WIP and host a poll for our Sinners (paid tiers).
Thanks for your interest in our game.
Cheers!