Freeze all enemies: Collect the prize in the middle of the screen while
the "Extra" apple at the top of the screen is on a red
letter.
Shoot through walls: Mr Do can shoot through tunnels that are separated
by very thin walls.
Flattened Mr. Do: Cause two adjacent apples to fall and intentionally
get underneath the first apple. Mr. Do will be flattened, but
will not lost a life. Note: The game must be restarted to continue.
