Blaster Master Zero Cheats - Nintendo Switch
Area 9 and True Ending
In order to access Area 9 and achieve the true ending, defeat the Mutant Lord at the end of Area 8 after defeating all other bosses, collecting all area maps and obtaining all upgrade items for SOPHIA, including Life Ups, Main/Sub Weapons and Maneuvers.
Clear Area 9 and achieve the true ending to unlock Ultimate Mode, accessible from the Extra menu at the title screen. This lets you replay the game using SOPHIA Zero, with all area maps and upgrades already unlocked.