Maze mini-game:
Press Down(2), Left(2), Right, B at the main menu.
Blockade mini-game:
Press Up(2), Left, Right, Left(2), Right, L at the main menu.
Alternate screen:
Press Up(2), Left, Right on the title screen.
Screen saver:
Press Left, Right, Down(2), R at the "X-Mail" and "Newsletters" screens.
Change screen font:
Enter the following controller actions at the player selection screen.
Rainbow font
Press Left(2), Up(2), Right(2), Down.
Green and yellow font
Press Up(2), Right(2), Down(2), Left.
Searchlight font
Press Down(2), Left(2), Up(2), Right.
