Sonic & Tails © 1993 Sega Enterprises, Limited.
Game ID: G-3331
* Stage Select: At the title screen, press Up, Up, Down, Down, Right, Left, Right, Left, START.
* Sound Test: At the title screen, press Down, Down, Up, Up, Left, Right, Left, Right, START.
* Sonic Hadouken: At the Sound Test screen, enter Left, Down, Right, Right+(1 or 2) to make Sonic do a Hadouken. (This is better known as a Street Fighter "fireball", and is the same key sequence as in that game)