In Hitori 9x9 #1 Light is played on a square grid. At the beginning, all cells contain numbers. The goal is to paint several cells so that there are no duplicate numbers in any row or column, as in the enabled state of Sudoku puzzles (except that black squares are added to the grid).

Neighbours 9x9 #2 Very Hard (another name is Neighbours, Nachbarn) play free online. In this variant of the puzzle there are additional conditions. In adjacent cells, separated by a bold line, there are consecutive numbers. Numbers between which there is no line cannot be consistent.

Rules and decisions of Sudoku Windoku 9x9 #8 Light solve play free online. An intriguing new option that allows surprising reasoning. Fill in all the fields so that each row, each column, each sector 3×3 and each sector of a different color contain all numbers from 1 to 9 without repeating.

Rules and decisions of Frame Sudoku 9x9 #8 The passionate architect Sudoku planned the cities based on his favorite pastime and arranged the buildings in rows and columns. This is a matter of restructuring cities, inserting numbers in the fields that indicate the floors of each building.

Compdoku 9x9 #3 - Other names are Hikaku (Puzzlephil), Greater-Than Sudoku, Comparison Sudoku. The puzzle is a 9x9 square, consisting of 9 smaller blocks, divided in turn into 9 cells. This version of sudoku does not contain numbers in the task - only comparison signs (“>” and “<”).

Rules and Decisions Sudoku Odd-Even 8 play free online. Solvers will find out how many new observations can be made with this unusual option. Fill in all the fields so that each row, each column and each 3×3 sector contains all numbers from 1 to 9 without repeating.

Irregular sudoku 8 (Sudoku Jigsaw, Kikagaku Nanpure) is a number puzzle. Translated from Japanese, “su” means “number”, and “dock” means “standing separately”. In a Irregular sudoku puzzle, the grid is a 9x9 square divided into smaller squares with a side of 3 cells (“regions”).