You can redeem download codes at Nintendo eShop.
If your download code is valid, you will receive various items upon entering it.
Once a download code has been redeemed, it cannot be used with another account.
You can register Ninjala Codes by accessing the corresponding option on the Mobile Menu.
Enter and submit a valid code, and you will receive a special item reward.
Reward items can be collected via email.
You must currently be online to submit a Ninjala Code.
Please note that Ninjala Codes differ from the Download Codes used for the Nintendo eShop.