there are lots of DS sudoku games
0363 - Puzzle Series Vol. 3 - Sudoku.zip
0480 - Sudoku Mania.zip
0481 - Sudoku Gridmaster.zip
0631 - Sudoku Master.zip
0654 - Sudokumaniacs.zip
0785 - Puzzle Series Vol. 9 - Sudoku 2 Deluxe.zip
and i haven't even gotten into the 1xxx's of releases yet.
if you're willing to search "sudoku" in any rom DB you are going to find at least 20 entries.