I guess I'm not smart enought for this game. Anyway it was a good riddle (somekind of).But:- the music isn't looped so it has finished after 2nd level at all- not to convenient UI (maybe some tutorial hightlights would be a good addition)
Thanks for the hints. You are very right about a tutorial being needed, there wasn't any time. Thanks for the music call out, that's a bug :)