Normal Sudoku Rules Apply. In addition, the 2 diagonal lines and the 4 colored window regions must also contain unique #'s 1-9.
You can use this link to play online: https://www.atksolutions.com/games/sudoku.html
Click newspaper/pencil icon and enter #: E21004
This is A fun and fairly easy puzzle so there is no need to run it through a solver.
Happy Valentines Day!