Free upgrades
On any map with a shop especially if that shop is near the entrance purchase one or more upgrades for one or more of your three summons Then press the Start button and select Restart Level Your Gold will be replenished but your summons will retain their upgrades
Kid Icarus Homage Password
PasswordEffectCARUS FIGHTS MEDUSA ANGELSStart partially through the game with only Shaedu
Metroid Homage Password
Password screen is found under Continue
PasswordEffectJUSTIN BAILEY Start partway through the game on hard with all upgrades and maximum money