Here is the full list of all 11 GOC Royale achievements.
Deal 100 dmg in a single hit.
Escape successfully an island in Quest mode
Win an Arena match.
Reach 60 strength in Quest mode.
Reach 75 agility in Quest mode.
Reach 100 endurance in Quest mode.
Reach 100 intelligence in Quest mode.
Reach 80 perception in Quest mode.
Reach 50 luck in Quest mode.
Reach 40 additional damages in Quest mode.
Reach 150 hp in Quest mode.