To unlock the Bonus Atari level pack, at the "Unlockables" menu, hold L + R and press X, Circle, X, Circle, X(2), Circle. Highlight "Episode 0" in Single-Player mode, then press Up to access the new levels.

Unlock the following characters by performing the corresponding tasks:

CHARACTER - HOW TO UNLOCK
Blue Ninja - Collect 500 gold or beat Episode 2 in Single-Player mode.
Gold Ninja - Complete all 45 episodes in Single-Player mode.
Green Ninja - Collect 700 gold or beat Episode 3 in Single-Player mode.
Pink Ninja - Collect 5,000 gold.
Purple Ninja - Collect 1,000 gold.
Red Ninja - Collect 300 gold or beat Episode 1 in Single-Player mode.

Unlock the following map packs by collecting the corresponding amounts of gold:

MAP PACK - GOLD
Blitz Map pack - 1,200 gold
Co-op Map pack - 2,500 gold
Domination Map pack - 3,000 gold
Tag Map pack - 3,500 gold

Unlock the following animations by collecting the corresponding amounts of gold:

ANIMATION - GOLD
Victory Animation 1 - Collect 400 gold or beat Episode 1 in Single-Player mode.
Victory Animation 2 - Collect 800 gold.
Victory Animation 3 - Collect 1,100 gold.
Victory Animation 4 - Collect 1,500 gold.
Victory Animation 5 - Collect 10,000 gold.

Unlock the following music by collecting the corresponding amounts of gold:

MUSIC - GOLD
Bonus Music 1 - 900 gold
Bonus Music 2 - 20,000 gold