All Sudokus in this test are based on a simple theme 'diagonals'. Apart from classic Diagonal Sudoku and Little Killer, some grids like Argyle, Pointing evens, Anti-diagonal, Queen, Diagonal consecutive are brought back into fashion
Diagonal creasing, Diagonal outside, Diagonal skyscrapers, Twin grids, Arrows battle are novelties types in this test.
Author is Frédéric Stalder:
http://logicmastersindia.com/M201203S/