The Downpour Add-on for Rain World has 13 achievements worth 195 gamerscore.
Find a destination for The Hunter's starting payload
Complete the game as The Hunter
Find the canonical ending to The Gourmand's campaign
Complete the game as The Artificer
Find the canonical ending to The Rivulet's campaign
Find the canonical ending to The Spearmaster's campaign
Complete the game as The Saint
Clear every challenge in Challenge Mode
Clear every milestone quest in Expedition Mode
Complete the Martyr passage
Complete the Nomad passage
Complete the Pilgrim passage
Complete the Mother passage