Is there a way to make differently colored paths cross? I can't do it UI-wise, it will always think I want to shorten the path I move onto. If that's not possible, level 4 seems impossible to solve to me.
Nice game, I usually don't ask for clarifications if I'm not interested. I did study the website, and I didn't find "dragging", ist just says "LMB". For me that means clicking, and it does work for 3 levels, so it becomes hard to understand that clicking is more of an "accidentally" working mode.
But interface design is complicated, again, the game looks and plays fantastically, I'll play more of it later.