Have Vincent join your party

Score 10,050 points or more in G-Bike at the Gold Saucer

Use a summon Materia in battle

Defeated the Leonine Misbegotten

Get Don Corneo to choose Cloud over the two females

Use a Limit Break

Shoot the imposter.

Earn 30 Relics (gold or better).

Seek and destroy. Again.

Shoot a background UFO in Future Tense.

Shoot 5 of them in a single level.

Discovered the Secret Exit in Road Crash.