This game is free to play and open source now. But we would be really happy if you will be able to host your own server and maybe even lead the more active development for the project. Feel free to discuss it at this Discord server (we have much more now).
This game requires at least Windows 10 (with Edge or Chrome browser for best experience). It can somewhat run on Android tablets/phones. It used to work on iPad too, maybe it still does, maybe it works even better now.
If game freezes when tab is inactive - disable "Calculate window occlusion on Windows" and "Enable sleeping tabs" (optionally) by visiting "chrome://flags".