Love this game. My favorite type of puzzle. I also like that there are so many puzzles, but I kinda wish that you can do the higher difficulties from the get go.
@purplecowadoom, actually, these puzzles are nonograms, named after their inventor, after a couple of years, Nintendo took the puzzles and released as a game, renaming it Picross. If Nintendo can take puzzles and rename it, so can this developer. I'm sure there are also copyright issues if Picross was used.