Here are some cheats and tips for the game Sonic Labyrinth.
Level select:
Press Up(2), Right(3), Down(6), Left(9), Start at the title screen.
Select the “Config” option and use Left or Right to choose a
starting level.
Bonus level:
Enter the cannon in zone 2-3 and press 1 + 2 + Right. Turn on the
switch to open the door to the bonus level.