If the screen flashes green or black before the title screen appears, the codes are loaded.
The honest answer:
The biggest "cheat" in the game is skipping the grind required to fight the strongest teams. In Strikers 2012 Xtreme , the story mode progresses through the events of the anime. However, beating the game is only the beginning. Inazuma Eleven Strikers 2012 Xtreme Cheat Codes