Price of levels are insane, would take years of grinding to unlock them all with just regular play.

Generally not fun. Very annoying zooming and dragging constantly. No additional game mechanics or anything. You are better off just printing them out, but you would still have to invert them to do that unless you want to deprive the world of black ink.

Color feature is to color lines, surely people want to color inside the lines if anything, very odd choice.