In Level 1 when an apple appears in the first 2 rows keep it in place by building a tunnel from the bottom of the screen to the location directly below it with a thin layer of dirt. Kill all the enemies except one and then intentionally lose your lives until you only have one remaining. Position yourself under the apple and dig the dirt under it so it will fall on Mr. Do when you shoot the enemy. Wait for the final enemy to approach and kill it before the apple hits Mr. Do. The game will glitch if you have done it correctly and the life counter will increase to 255 (don't earn a Bonus life as it will set the counter to 0). This glitch only works with the Taito version of the game.