thank you! there is a donate button, but if I wanted to sell it I should have probably made a steam page, trailer, got wishlists, made proper menus, used another engine, all that - in short, taken it much more seriously. Maybe I’ll do it in the future?
the game is a .html file (+ a .ogg music track), which you can download in some way using the browser developer tools, but that's definitely not the most accessible option ^^
if the website was open and you lose internet, you can keep playing. the progress should get remembered. might be good to write down where you left off, levels can be skipped in the level select!