A single hit from enemy attack means death
Enter the following at the password screen: LDMSLRDD

All healing items turn into temaki sushi
Enter the following at the password screen: SLLMRSLD

Enemies' attack power doubled
Enter the following at the password screen: MSRLSMML

Enemies' defense power doubled
Enter the following at the password screen: SLRMLSSM

Healing items are no longer available
Enter the following at the password screen: DMLDMRLD

Ougi gauge is always full
Enter the following at the password screen: RRDMLSDL

Shuriken no longer available
Enter the following at the password screen: LLMSRDMS

Turtles can carry unlimited number of shuriken
Enter the following at the password screen: LMDRRMSR

Turtles no longer take damages
Enter the following at the password screen: MDLDSSLR