Backslash L(2,4) D(21,12,2,2,1,0)
V Difficult
Must have unique characters in each row and column but the 3 by 3 boxes are replaced by backslashes. These wrap left to right and top to bottom so the overall geometry is a doughnut (torus)

People L(2,3) D(19,19,2,2,0,0)
Difficult
The shapes have “lumps” on each side to become quite irregular. They look to me like little people. This problem wraps top to bottom and side to side so the overall geometry is like a doughnut (torus).

Sudoku 9X9 L(1,2) D(28,10,1,0,0,0)
Gentle
This is the standard geometry that is usually seen. Characters must not repeat in rows or columns or in any of the 3 by 3 boxes that are outlined.

Toroid H L(2,1) D(25,6,0,0,0,0)
Moderate
The normal 3X3 boxes are replaced by horizontal stripes (helices) which wrap around the problem. These stripes join the left side to the right side and the top to the bottom so that the overall geometry is a doughnut (torus).

Tred 01 L(2,1) D(28,5,0,0,0,0)
Moderate
Tredoku 3 dimensional problem 01 with 7 faces, 6 rows and 6 columns

3D 4X4 Cube L(2,1) D(29,5,0,0,0,0)
Moderate
True 3 dimensional problem. Each 4X4 square is one plane of a 4X4X4 cube. Consider the squares stacked on top of each other. There are 12 planes in this problem each of which is a 4X4 square which must have no repeating characters. Some of the planes are highlighted. There are 16 possible characters so I use a standard hexadecimal character set: 0,1,2,…,9,a,…,f.

Diamond L(2,1) D(23,8,0,0,0,0)
Moderate
Here the shapes are pushed over to become diamonds. This wraps side to side but not top to bottom.

Sudoku 9X9X L(1,4) D(21,17,4,2,1,0)
Difficult
As regular 9 by 9 but must also have unique characters in each diagonal, highlighted.

Toroid V L(2,1) D(19,8,0,0,0,0)
Moderate
The normal 3X3 boxes are replaced by vertical stripes (helices) which wrap around the problem. These stripes join the left side to the right side and the top to the bottom so that the overall geometry is a doughnut (torus).

Tred 02 L(2,1) D(28,6,0,0,0,0)
Moderate
Tredoku 3 dimensional problem 02 with 8 faces, 6 rows and 9 columns

Film L(2,1) D(24,7,0,0,0,0)
Moderate
Similar to the regular 9 by 9 Sudoku but the squares have lumps in the top and bottom. The problem wraps top to bottom but not side to side so the overall geometry is a cylinder.

People L(2,1) D(21,14,0,0,0,0)
Moderate
The shapes have “lumps” on each side to become quite irregular. They look to me like little people. This problem wraps top to bottom and side to side so the overall geometry is like a doughnut (torus).

Sudoku 9X9 L(1,1) D(31,6,0,0,0,0)
Easy
This is the standard geometry that is usually seen. Characters must not repeat in rows or columns or in any of the 3 by 3 boxes that are outlined.

Toroid H L(2,1) D(19,11,0,0,0,0)
Moderate
The normal 3X3 boxes are replaced by horizontal stripes (helices) which wrap around the problem. These stripes join the left side to the right side and the top to the bottom so that the overall geometry is a doughnut (torus).

Tred 03 L(2,1) D(29,5,0,0,0,0)
Moderate
Tredoku 3 dimensional problem 03 with 7 faces, 6 rows and 6 columns

4X4 Cube L(2,4) D(42,17,4,3,1,0)
V Difficult
Strictly a 2 dimensional problem since only considering the outside faces which are laid out onto a plane. There are 16 Characters which cannot repeat in any band or face. 3 of the bands are highlighted. There are 12 bands and 6 faces, each with 16 Cells. There are 16 possible characters so I use a standard hexadecimal character set: 0,1,2,…,9,a,…,f.

Jigsaw L(2,1) D(25,7,0,0,0,0)
Moderate
As regular 9 by 9 but the normal 3X3 boxes are irregular shapes

Sudoku 9X9X L(1,4) D(20,16,3,2,1,0)
Difficult
As regular 9 by 9 but must also have unique characters in each diagonal, highlighted.

Toroid V L(2,1) D(20,11,0,0,0,0)
Moderate
The normal 3X3 boxes are replaced by vertical stripes (helices) which wrap around the problem. These stripes join the left side to the right side and the top to the bottom so that the overall geometry is a doughnut (torus).

Tred 04 L(2,1) D(37,6,0,0,0,0)
Moderate
Tredoku 3 dimensional problem 04 with 10 faces, 6 rows and 12 columns