Invincible
Input the invincibility code to make the game easy or to just enjoy the storyline. The code will make it impossible for your character to suffer any damage. During the opening movie, press "Up," "Down," "Left," "Right," "B," 'A," on the controller. You will hear a chime to verify the code was put in correctly. Open a new or saved game and continue the game as normal, only now the character will be invincible.
Level Up
If you are having a hard time beating a quest, go back to a previous area and fight enemies to make Goku stronger. This form of leveling up will improve Goku's attack and defense points. For example, if the battle with the first boss, Radditz, is too difficult, go back to the forest village area and level up until you are a level seven. A good rule of thumb after failing a boss fight is to go back and pick up two levels before trying again.
Save Often
Sometimes you will face an enemy that is too difficult and you will be defeated. This causes you to start at your last save spot. Save often so you don't lose progress. You should save after every boss battle and quest.
Solar Flare
At any time, use the "left trigger" button to ready the solar flare move, then hit "B" to activate it. The move will stun all enemies on the screen and render them unable to attack. Unload attacks on them while they are stunned. The longer you hold the "B" button before releasing it, the more of a charge the flare will have. Charge the solar flare before you see any enemies on the screen. You want the flare to be ready as soon as you see a foe, and you don't want to waste seconds charging it when they can see you.