Fresh off the heels of that update, a new level's available in the full version. ...which itself is out of free-to-keep. Still pretty cheap for now, though. But if you've already downloaded it, you've still got it.
From here on, pretty much every option and quality of life update will also be added to the demo version -- the main difference between the demo and the full version will be the levels available. Saved games should additionally automatically transfer between the demo and full version -- seems to work in my own testing.
Levels might be tweaked or reordered during Early Access.
Happy tiring!
