I got some sort of scaling working for now until I switch to sprites for the markers. I ported all of Picross DS easy levels for now but I haven't set win/loss conditions + mistakes yet. Those are the least interesting bit to code. Comparison could be check by bitwise and over between the reference sprite and the map and checking the sum of all of the non-masked cases. I hope it's faster than just iterating through the userdata.

#Picotron

Note for self:
- I use :drag to drag over and paint cases. Something to inhibit drawing if the player made a mistake would stop accumulating mistakes in a single stroke.
- Building a sampling list from the reference sprite and feeding an intermediate userdata by sampling the map with that list and sum-folding the result might work too.