Hard, 100 puzzles

Hidden pairs, triples and X-Wings. Each puzzle needs at least one genuinely hard move, and the book is ordered from gentler to nastier so it grows with you.

Puzzles: 100
Hard: 100
Pages: 118 per device
Files: Paper and Paper Pro
Solutions: Included, linked both ways

Downloads work forever. Your pack is stored as a seed rather than a file, so an expired copy is rebuilt byte for byte identical.