Here is the full list of all 40 One Piece Pirate Warriors 3 achievements. It takes around 100-120 hours to unlock all of the achievements on Windows.
Increase 20 or more character's Crew LEVEL to MAX.
Achieve 100% Legend Points in all episodes.
Complete the "Final Island" in the Dream Log.
Unlock all Characters.
Break through one Character's growth limit.
Complete the Dream Log.
Complete 15 or more islands in the Dream Log.
Complete five or more islands in the Dream Log.
Obtain 100 or more types of Coins.
Use Hero Power at least 100 times.
Obtain 20 or more Skills.
Complete the Final Chapter of the Legend Log.
Defeat over 100,000 enemies.
Complete the Fourth Chapter of the Legend Log.
Defeat over 10,000 enemies using Special Attacks.
Complete the Third Chapter of the Legend Log.
Defeat over 10,000 enemies using Kizuna Attacks.
Obtain 50 or more types of Coins.
Increase one character's Crew LEVEL to MAX.
Defeat 300 enemies using a single Kizuna Rush.
Complete the Second Chapter of the Legend Log.
Unleash a Special Bond Attack with four Crewmates.
Complete 25% or more of the Gallery.
Obtain 20 or more Skill Posters.
Achieve 100% Legend Points in a single episode.
Complete the First Chapter of the Legend Log.
Use Kizuna Attacks of 3 different Crew mates in 1 battle.
Change Crew members for the first time.
Obtain one Skill.
Unleash your first Hero Power.
Obtain one Coin.
Obtain one Skill Poster.
Get an S-Rank Results Evaluation for a single episode.
Complete the Legend Log Prologue.
Unleash your first Kizuna Rush.
Unleash 20 or more Kizuna Attacks in a single battle.
Defeat 1,000 enemies in a single battle.
Unleash your first Kizuna Attack.
Obtained all achievements.
Complete the entire Gallery.