I just launched Chedoku puzzle which is a Chess based puzzle game that is very similar to Minesweeper and Sudoku.
To solve a Chedoku puzzle re-arrange the chess pieces to find a solution where the number of pieces threatening each square matches the large number in that square. Chess rules are only used to calculate the threat numbers. You can move pieces freely and place them anywhere.
Please try the website and let me know if you like the game. I am especially interested in comments on design and usability of the website.