Hey ! :D Where can I contact the dev' ? :D

I'd like to backup my 100% game progress. Where is it saved? Also checked https://www.pcgamingwiki.com/wiki/.Projekt , but it's not listed there.

really, i hate it, i hate it, when i have the first solution and the game switch to next level. no damn hell, i want play the same level and find the second and/or third solution. so ffs, give me a "next level" button and delete the damn auto switch after the first solution....

http://steamproxy.com/sharedfiles/filedetails/?id=1335565509 this is annoying. and a joke, a bad one to be honest.

What is the picross mode and how can I turn it on?