Dragon Ball Z: The Legacy of Goku

If you are wandering around in an area and are low on health, you can try this (not-so-secret) trick to recover quickly. Save your game, then shut off the game and turn it back on again. When you appear back where you left off, you'll be back at full health/Ki without even using items!

In the options menu, highlight "Text Speed", hold L+R+Up (thus now highlighting "Exit"), and press A to access a debug menu containing a level select, sound test, sprite viewer, and photo gallery.

Fly away from the boss until he's about 1.5 - 2 screens away from Goku. You can keep shooting the boss with Ki Blasts from there and the boss won't move. You can find a place to shoot by firing Ki Blasts in the boss's direction and moving side to side until it makes the sound that it makes when you hit an enemy with a ki blast. Once you find the place where you hit the boss, stay there and keep firing Ki Blasts. It works because bosses don't move when you are a certain distance away from them. For some bosses, after you fire ki blasts for a long time, you might need to go up to the boss and punch him/her because there are some bosses where you need to be on the same screen as the boss.

When an enemy attacks you with an energy attack just hit the R button to fly, when you get hit by the blast Goku will land but your flight meter will still show. This allows you to have Infinite Health. You can deactivate the glitch by pressing the R button again to fly and hit it again to land. Though you can not see it your Ki will go down when you shoot it.

During the intro movie, press the following buttons. If done right, a sound effect will confirm your entry. Start a new game or continue a saved game, and when an enemy attacks, you will not receive any damage.