Unlimited continues: Press B(3), C, A(3), B(2),
C(3) at the title screen. The phrase "Free Play"
will appear at the bottom of the screen to confirm correct code
entry.
Invincibility: Press A, B, A, C, B,
C(2), B, C, A, B, A
at the title screen.
Information in this section was contributed by imaknutt.
Level select: Press C, A, C, B, C,
A, B, A, B, A, B, C,
A at the title screen. The phrase "Zone Select"
will appear to confirm correct code entry.
Extended high score screen: Press A, B, C, A, B,
C, A, B, C, A, B, C
at the title screen.
Information in this section was contributed by imaknutt.
Sound test: Obtain a high score and enter ZZT as initials
on the high score screen.
Debug data: Press [A, B, C] four times at
the title screen.
