While breaching the water in dive mode, pass over land before entering the water once more.
Collect your first relic.
Unlock your first plane.
Encountered the Sunfish.
Encountered the Flock.
Encountered the Luminous Archivist.
Encountered the Hydra.
Visit your companions.
Collect every relic in the Inverse.
Unlock all planes.
Fly into a world's sun.
Pollinate the Accordion Blooms in the Sunchamber.
Cut down a hanging tower block in the Sunchamber.
Encountered the Leviathan.