Sega Master System / Mark III / Game Gear
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 hit ratio of 100% and you will receive a massive 50000 points bonus.
On the Game Over screen, don't press anything. The game will return to the Sega Mark III logo; during the logo, press x5, x3 (if playing as Player 1) or x3, x5 (if playing as Player 2). When you start the game you will continue from the stage you died on.
During the title screen, press . A secret message will appear: うどんこ こんどう, which is pronounced "Udon-ko Kondou", which has no obvious meaning.
See the main page for The Ninja (ザ・ニンジャ, 忍者, 인자)