Hello, this game is incredible, but I have the full version and I've been waiting for an update for a long time.
If you have version 2.1.1b (you'll see the version number on the title screen), then you have the latest version (and we're not currently planning any future content updates). If not, go to your downloads page on itch.io and you'll find the latest version there (it should auto-update if you're using the itch.io client, otherwise you have to re-download the update manually).