The game is by all means a masterpiece. Its biggest asset is the gorgeous graphics. The music is also really nice. Gameplay is good.
However... I personally don't like the story, it's too fictional. Undead pirates, cartoony zealots, talking ship. In this sense it is still inferior to Desperados III, which is, in my opinion Mimimi's greatest achievement.
If you've played some of their previous games (Shadow Tactics, Desperadoes 3) then you'll know what to expect. If not, definitely look into them, they're great!
It's a stealth tactics game where the missions can feel like puzzles to solve. The major difference between this and the previous games (other than setting) is that you can choose who to bring with you on the mission, and some maps are re-used. That's not as bad as it sounds, because you don't have to clear the map to succeed at your objective, and you may end up exploring entirely different areas or routes on different missions.
Not to mention, it's a big playground with the different characters and their abilities. You're free to think of creative combos - have Gaelle load Quentin into her cannon, shoot him into a high spot, then he can use his fishing pole to pull her up with him. There's way more like that, and the characters have a lot of personality to match the outlandish setting.
Some players may not like the activities on the ship between missions, but they're pretty optional. I thought they were fine for what they were.
No one else is really making games like this, and they're worth experiencing if you enjoy stealth, tactics, and really thinking your way out of tricky situations.