Bounder

Unlimited lives:
Hold 1 + Q + A + Z + [Space] at the title screen for approximately thirty seconds. The screen border will change color to confirm correct code entry.

Unlimited balls:
Load or reset the game, then execute the following BASIC command before running or restarting the program.
POKE 2099,173

Unlimited jumps:
Load or reset the game, then execute the following BASIC command before running or restarting the program.
POKE 7543,173