The Hardest Killer Sudoku And How To Solve It
23:01
A Tetris-Flavoured Killer Sudoku?
29:38
Greater Than Killer Sudoku: Another extremely hard puzzle
40:38
Our Hardest Sudoku And How To Solve It (Slowly!)
1:03:48
The 6x6 Miracle Sudoku
21:18
Expert Sudoku: The Basic Techniques Used By Champions
20:04
Diabolical Sudoku: One Trick Is All You Need!
28:03
Extreme Sudoku: Wings, Skyscrapers & Empty Rectangles
29:27