Here is the full list of all 20 Aritana and the Twin Masks achievements worth 1,000 gamerscore.
Overcome the Sun's Challenge.
Overcome the Moon's Challenge.
Find your way to the YpY Temple.
Find Raoni's lost Staff.
Find the Sun's Bow.
Cleanse the Nest in Tupã's Garden.
Cleanse the Nest in Iara's Lake.
Cleanse the Nest in Caaporã's Watch.
Defeat the masked man on the top of the Temple.
Perform 100 teleports using the Temple energy.
Shoot ten flying projectiles.
Shoot 1904 arrows.
Kill ten enemy turtles shooting its core hidden ten times.
Collect three recipes.
Collect all recipes.
Find five Muiraquitãs.
Find all Muiraquitãs.
Kill a special turtle.
Destroy a crystal near an enemy five times.
Kill all Special Turtles.