Unlock Battle Arena 
To Unlock Battle Arena, earn all the Grades, Then you should get the Master 
Grade. The Battle Arena Will be open at Robot Beach

Level skip:
Press Start to pause game play, then hold R1 and press Square(3), Circle. 
Release R1, then hold L1 and press Triangle(2). 
Release L1, then hold and press R1, Square(2). 

Upgrade sword:
Press Start to pause game play, then hold L1 + R1 and press Circle, Square, 
Circle, Triangle(2), Square, Circle, Square. 

Big head mode:
Press Start to pause game play, then hold R1 and press Triangle(4). Release R1, 
then hold L1 and press Triangle(2). Hold R1 + L1, then press Triangle, Circle, 
Triangle 

Get stronger swords:
To get stronger swords, you have to kill enemies. Notice that when you complete a 
mission (at the blue screen with Ninja floating), there is a sword at the bottom of 
the screen called "Ranx Bank". The sword has numbers that increase with the 
more "Ranx" that you kill. Also, the more "Ranx" you kill, the sword gets covered 
in Ranx blood. When the sword is full of Ranx blood, at the "Mission Complete" 
screen, Ninja will be holding his old sword. He will drop the old sword and a new 
one will fall into his hands.

xPower-Ups:
Whenever you kill an enemy in a rapid succession, the number to the right of the 
health bar increases by one up to 10. This represents what points you receive for 
killing an enemy, multiplied by the number displayed. This is useful in certain 
missions where a high score is required to earn the grade.

Mow grass:
Where there are grass, flowers, mushrooms, other foliage, objects other than 
crates and barrels, and certain decorative objects, you can cut them down to earn 
a few extra points towards your main score. This is useful in the certain levels that 
require a high score to earn the grade.

Defeating Malakai:
In the first part (where there is lava for a field), keep a steady pace while jumping 
around on the stones. Hold Forward and the direction that you want to jump and 
collect the shuriken. Throw it at him without locking on. After throwing the full 
amount of eight shuriken three or four times, he will fall down into the lava. Then, 
he will jump up and absorb the lava. You will now have to sword fight him. The 
Soul Sword and Revive Rage are recommended for this. If you run at him and 
slash repeatedly, you are going to get hammered. The best times to attack him 
are when he just finishes a quick slash and when he is just about to do the non-
shock wave ground pound. Hit him at those times and use Berserks and Insane 
Rages every time you do not need to revive. 

Defeating O-Dor:
Attack his belt. After you attack it twice, he will slam his fist. You can now attack it 
two more times before he slams you away.

Sword list:
Notice that the sword color changes in the your belt changes.
1. Ninja's Sword
2. Golden Sword
3. Jade Sword
4. Sapphire Sword
5. Fire Sword
6. Soul Sword 

Healing:
If you are low on health, try to find some weeds and chop them down. Notice that 
your Rage Ability switch will gradually increase. Keep chopping down weeds and 
you will soon be able to use your "Ninja Revive" to heal yourself.