Game freezes on "Lake of Good and Evil" level.
roboq6, looks very strange. On Mac and Windows all works fine, but I never tested it on Linux.
You can try to clear browser cache.
You can also try to use another browser (to use current saves in another browser, go to game settings -> copy login -> go to game in another brother -> go to setting s-> input old login -> click set -> refresh game)
In few days I try to test it on Linux.
Bad news: I was unable to copy-paste my login. For some strange reasons the clipboard just ignores all attempts to cut or paste from/in the game.
Good news: I started the game from the scratch in another browser called Chromium (Opensource fork of Google Chrome) and was able to beat level "The lake of Good and Evil" without any problems. The version of Chromium is 69.0.3497.92
I will update build in next 2 days.
But cause itch.io doesn't supports saves along different builds, you should copy login (each symbol by hand) from game setting and save it. Then after build updates enter your login in setting. Sorry for this disadvantage.
Also may be clear cache or browser update can help.