If you're looking for a game that's like assasins creed Black flag, or even enjoyed that game. Then this game is for you.
I read a lot of reviews and that alongside the hype I assumed would see this game a failure, I was wrong.
It's fun, addictive, well thought out piracy at its best. The level up mechanics for the ship building and weapons systems make that grind for the materials a very smooth but also rewarding experience.
The graphics are stunning. The sea in itself is hypnotic to loom at with its shifting shades that alter with the weather and the luminance of the sky.
The amount of customisation is unreal. It is not pay to win in any way. The only thing you can pay for are cosmetics that are purely cosmetic. There are no power bonuses or options to level up by paying.
In fact most of the cosmetics I prefer were found in the game exploring. Not in the shop.
In the sea on your ship the game is very open world, you can do most things from your ship. On land its very linear. Small areas with merchants but not much land exploration, and honestly... it doesn't need it.
The game is great.