You defeated Mother Brain and finished the game.
You defeated Dark Force.
You reached level 30.
You watched the entire in-game credits roll.
You used a Hidapipe.
You used an Escapipe.
You reached level 20.
You opened all four dams.
You acquired the Laser Cannon.
You reached level 10.
You reached the Tower of Nido.
You spent 1,200 Meseta on one item.