To acces special menus on menu screen:
Kool stuff:     select, a, b, right, left, up, up, down, down
Kooler stuff:   up, up, down, down, left, right, a, b, a
Scotts menu:    x, b, a, y, up, right, down, left, down
Sound test:     a, y, b, x

To play as Shao Kahn: At the menu screen press x, b, a, y, up, left, down,
right, down and you should see Scott's menu pop up. Go into the menu and enable
Shao Kahn. Next, on the character select screen press start controller 2 and you
should see him in the middle square.
To play as Motaro go again to the main menu and press select, a, b, right, left,
down, up, up. You'll see the Kooler Stuff menu pop up, go into the menu and
enable Motaro and then do the same like Shao Kahn.