BACK TO PUZZLE will bring you back to the current game, where you suspended.
SHOW SOLUTION will show the solution of the current Sudoku (the current game cannot be resumed in this case, you can only start a new one).
RESTART PUZZLE will restart current puzzle (you will lose what you have done on it).
PRINT PUZZLE will print current puzzle, if you have a printer installed on your system.
QUIT PUZZLE will abandon current puzzle, and you can start a new one with different settings.