Here is the full list of all 16 RWBY: Arrowfell achievements.
Complete Chapter 5.
Max out all skills for team RWBY.
Defeat 25 enemies with Yang's Semblance.
Defeat 25 enemies with Blake's Semblance.
Defeat 25 enemies with Weiss' Semblance.
Complete Chapter 4.
Complete Chapter 3.
Hold 10 Skill Points at once.
Complete Chapter 2.
Defeat 50 enemies using projectile attacks.
Complete Chapter 1.
Purchase an item from a Merchant.
Dash 50 times using Ruby's Semblance.
Defeat 50 enemies using melee attacks.
Open a chest.
Complete objective at the Summit.