Here is the full list of all 18 Ruiga Pirates: First Survivors achievements.
Opening Game
Reach Level 10
Reach Level 25
Reach Level 50
Survive 1 minute with any captain
Survive 15 minutes with Katia
Survive 15 minutes with Barbarossa
Survive 15 minutes with Wokou
Survive 15 minutes with Gallo.
Hold 6 different weapons at once
Collect 20 Crates
Complete 1 Island Quest
Complete 10 Island Quest
Complete 50 Island Quest
Open 1 Chest
Open 25 Chest
Open 100 Chest
Open Five Star Chest