Here is the full list of all 32 PixARK achievements worth 1,000 gamerscore. It takes around 0.5-1 hour to unlock all of the achievements on Xbox One.
Explore the Doom Lands biome.
Take them away.
Collect your first apparel.
Tame your first companion.
Kill a Rex.
Tame a Quetzal.
Kill a Reaper.
Reach the level limit.
Kill a Behemoth.
Kill a Large Sea Slime.
Kill a Mummy King.
Kill an Ice Fairy.
Get a Mediterranean-style Building Blueprint.
Get a Bamboo-style Building Blueprint.
Get a Magic Academy-style Building Blueprint.
Get a Western-style Building Blueprint.
Get an Executive-style Building Blueprint.
Get any piece of SCUBA equipment.
Get any piece of lava equipment.
Find a Grassland Ruins and get a Grassland Ruins Brick.
Find a Desert Ruins and get a Desert Ruins Brick.
Find a Frozen Fortress and get a Frozen Fortress Brick.
Find a Swamp Ruins and get a Swamp Ruins Brick.
Find a Dark Dungeon Ruins and get a Dark Dungeon Ruins Brick.
Get a Sunken City Brick.
Tame a Sauropod.
Kill a Cyclops.
Open a beam of light.
Open a top-level treasure chest.
Explore the Dark Forest.
Explore the Frozen Lands.