Here is the full list of all 15 The Stranded Traveler achievements.
Open a coin chest
Pickup an enemy drop
Kill 25 enemies
Try your luck at the Gambler
Win once at the Gambler
Kill Elemental Boss
Drink a potion
Finish a level with 100 or more HP
upgrade something at the alchemist
Complete the moving water and wall run
Upgrade your characters HP
Visit another planet
Find out who corrupted the earth
Destroy an astroid while flying a spaceship
Destroy the corrupter of the earth and remove them from power