Full member mode:
Hold L1 + R2 + L3, then press Start at the title screen. A sound will confirm correct code entry. Alternately, successfully complete the game in story mode.

Gundam:
Hold L1 + L2 + L3, then press Start at the title screen. A sound will confirm correct code entry. Alternately, successfully complete the game in story mode.

Hyaku Shiki:
Hold R1 + R2 + R3, then press Start at the title screen. A sound will confirm correct code entry. Alternately, successfully complete the game in full member mode.

Hard difficulty setting:
Hold R1 + L2 + R3, then press Start at the title screen. A sound will confirm correct code entry. Alternately, successfully complete the game in full member mode.