Here is the full list of all 29 Salt achievements.
Dig up some buried treasure
Place a flag on a very tall mountain.
Decorate your boat with a painting.
Kill the Spider Queen.
Hold at least 50 lore books in your inventory.
Obtain over 10,000 gold.
Craft the Pardon Pusher.
Craft The Maiden.
Obtain a Hightop Bloom Flower.
Sail past the 1000 unit mark.
Obtain a set of Turtle Armor.
Fish up a Gigantic Mouth Seabass.
Fish up a Dragon Fish.
Defeat the Dark Guardian
Obtain the Loreman's Lofty Axe.
Defeat Draegan on Hardcore Mode.
Obtain the Golden Compass.
Obtain the Druid Spirit Idol.
Obtain a legendary item.
Get the Jungle Skimmy boat.
Obtain all journal inks.
Obtain the Lucky Fisherman's Hat.
Defeat every boss in the game.
Complete the main quest line.
Complete every merchant quest in the game.
Hunt and kill The Alpha Stag.
Map 100 islands at 100% accuracy.
Purify the Ancient Skull.
Knock fruit from a tree and shoot it with an arrow before it hits the ground.