No missable achievements (plus 17 unknown)
Sign in with Steam or Xbox to track your progress, and:
Learn the ropes.
See the Japanese wreck.
Get lost in the cave and come back safe.
Meet the French American.
See what the volcano buried.
Snoop around the ruined town.
Take the difficult path.
Discover the name of the City.
Explore the tomb of the king.
Stand in front of the altar.
Find the treasure of the City of Gold.
Look Neptune in the eyes.
Photograph the unicorn.
Swim past the guardian of Truth.
Get them all.
Explore the crypts.
Visit the armory.