Ninja

Continue game play:
In the Japanese version, wait for the Sega Mark III logo to appear after the "Game Over" screen. Then, press Up five times, Down three times.

Bonus lives:
Note: A controller with an auto-fire option is recommended. Locate the round tree on the right side of the first screen of level 1. Eliminate the first Ninja that appears. Approach the tree and shoot it for approximately fifteen minutes. Complete the level with 0% to receive ten lives and a large amount of bonus points.

Get a 0% accuracy in any level. Your accuracy bonus at the end of the level will be 9,999,999, which will result in ten bonus lives. Note: This can only be done once.