Here is the full list of all 40 Relicta achievements.
The base game contains 27 achievements, and there is 1 DLC pack containing 13 achievements.
Complete the first area of Sverdrup dome
Activate the antenna to contact Ragnar
Complete the first area of Faustini
Complete the second area of De Gerlache
Complete the second area of Shoemaker
Complete the first area of Shoemaker
Find a collectible
Find a PDA data card
Complete the first area of De Gerlache
Complete the prologue
Find 50% of collectibles
Find all collectibles
Find 50% of PDA data cards
Find all PDA data cards
Complete the third area of De Gerlache
Complete all puzzles of De Gerlache dome
Complete the third area of Shoemaker
Complete all puzzles of Shoemaker dome
Complete the second area of Faustini
Complete all puzzles of Faustini dome
Complete the second area of Sverdrup
Complete all puzzles of Sverdrup dome
Complete all puzzles of Relicta
Meet the parasite
Run away with Kira
Stay and wait for Ragnar
Complete Relicta in less than six hours
Complete the first puzzle of the day
Complete four puzzles
Complete eight puzzles
Complete all the puzzles of the day
Use the magnetic abilities for the first time