Yes our game was actually working fine but when we tried to build fore Webgl as you said it wouldn't load the levels at all. It is a Unity 6 problem as we understood and we couldn't find a single solution on the web. So we tried fixing it the last our and broke the actual game more.
Every level was like the first level but somehow they weren't working at the windows build. Thanks for liking the game tho and we agree that it needs polishing.