Here is the full list of all 29 Salt achievements.
Hold at least 50 lore books in your inventory.
Decorate your boat with a painting.
Place a flag on a very tall mountain.
Obtain a set of Turtle Armor.
Craft The Maiden.
Obtain a legendary item.
Obtain a Hightop Bloom Flower.
Dig up some buried treasure
Obtain over 10,000 gold.
Craft the Pardon Pusher.
Sail past the 1000 unit mark.
Fish up a Gigantic Mouth Seabass.
Fish up a Dragon Fish.
Defeat the Dark Guardian
Kill the Spider Queen.
Obtain the Loreman's Lofty Axe.
Defeat Draegan on Hardcore Mode.
Obtain the Golden Compass.
Obtain the Druid Spirit Idol.
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.