3D Picross does this with some of the puzzle books:.Picross S3 introduces Color Picross, which requires you to not only fill cells but also fill them with the correct color.However, each sub-puzzle has to be unlocked first by completing end-of-row puzzles in standard Picross mode. Picross S2 introduces Clip Picross, in which you are given an assortment of sub-puzzles of varying size to complete and completing them all forms an overall picture.Some of the Picross-e games have Micross, where you start by completing an 8x8 "overall puzzle" and then each filled block has a 10x10 puzzle of its own to complete.These big numbers mean "there's a run of this many filled blocks that is exactly two columns wide."
Unlike other games, Nintendo does put a cap on how much real money you can spend (after which Picrites are free), but that cap is around $30 when each Picross-e download is only $6. Picrites can be received for progressing through the game or by completing the daily challenges, but not very quickly on average it takes about a week and a half to unlock each new set of puzzles. Allegedly Free Game: Pokémon Picross runs on this model with "Picrites", a currency that needs to be spent to do anything beyond just solving available puzzles.