In Pokémon Picross, there are some areas that are locked by passwords. The passwords can be found here (no spoilers here). Enter the password according to your game region. If you have a region-free dump, try entering the code for the game region of the game you’ve dumped from. No internet connection is needed for that.
As for the in-game currency, Picrites, you can’t buy them since connecting to Nintendo Online is not supported. So, there’s a simple hack to get a lot of it.
- First, go to Pokémon Picross’ save editor.
- Open the save data on the website (it can be found by right-clicking the game in Citra).
- Set the no. of bought Picrites to 5000, and save the file.
Buying 5000 Picrites in-game gives access to unlimited Picrites.
- Replace the old save file with the new one.
Now whenever you play the game, you can add more Picrites by going to the shop and tapping the button, which will add 1000 Picrites per tap.