Ninja Gaiden DS - Secrets and Tips

Unlockables

Head Ninja mode

Beat the game once on Normal mode

Master Ninja mode

Beat the game once on Head Ninja mode

Master Kunoichi mode

Beat the game once on Normal mode.
Defeat the Red Dragon boss at the beginning of the game with Momiji.
This mode allows you to play as "Rin"; actually she's the unmasked Momiji.
Here's a video guide of the battle with Red Dragon by using Momiji.

Prize

Beat the game once on Normal mode.
The availablities under this section are based on your Wood Amulets collection.


Secrets

Happy Birthday sound

Play the game on your birthday (depends on your NDS setting), you will get a special "Happy Birthday" sound effect when you start the game! Instead of the usual sound effect when you tap the start screen.
(credit: amityville27)

Shoot for Blue Essence

In the Forest of Shadows, some Concentric Circles are around the Dragon Statue. Shoot the Concentric Circle to spawn the Blue Essence. But this is quite useless since the Dragon Statue is here.


Tips

Quick Ultimate Technique

The speed of the Ultimate Technique charge time is actually based on the quantity of Essences around. The more Essences are spawned (before you absorb), the faster Ultimate Technique you will get. You can charge a max level Ultimate Technique instantly as long as the floating Essences are enough.

Keep The Essence Floating

As mention above, floating Essences shorten your Ultimate Technique charge time. Because the Essences will be obtained when your character has no action (attack), so other than keep slashing the enemies, press any button to guard or perform Reverse Wind are another ways to hold the Essences in the air.

"Paint" a Ninpo

Actually it's not necessory to follow the Ninpo letter as it shows on the screen, you can slide over the letter until the letter is fully filled with colour. And... the Ninpo is done.

Fake Ninpo Protection

Tap the Ninpo symbol at top left corner to perform a Ninpo, and your character will become invincible while charging up the Ninpo. Tap return symbol at bottom right to cancel it so you don't waste your Ninpo. This is quite useful when you couldn't dodge certain attacks from the enemy at the right moment.