3D Sudoku

This a revived version of the classic japanese game Sudoku. Use your brains to solve the puzzle, but you must have patience and the will to succeed. Choose from the 4 levels of difficulty. In Sudoku, each row, column and 3x3 sector must contain the numbers from 1 to 9. You don't have to guess to solve Sudoku Puzzles. Every solution is unique and logical. Checking numbers help you to figure out what to do.