So disclosure time: I loved Sid Meier's Pirates.
I bring this up because Windward is similar in a lot of respects to Pirates. Both are games where you and your crew sail around a large chain of islands and mainlands representing your chosen faction, attacking other ships, trading goods, fighting in wars, and gaining standing and reputation.
Where Windward differs, is in that it's a procedurally-generated game, and unlike Pirates, you never leave the ship. You sail from port to port, taking missions and leveling up your ship and equipment as you go. Occasionally, you can also get hot tips about commodities from different ports and various other rumors.
The experience of Windward is actually very meditative in a lot of places. There are a lot of moments where you don't have to go anywhere, just spend your time swanning around the immense map to a soundtrack of soothing flutes and occasionally getting into pirate battles. It actually reminds me a little of what a single-player game of Merchants and Marauders would be like. Which brings me to the multiplayer.
The multiplayer in Windward seems to be what the single player bulks everyone up for. The general structure is the same (go around doing missions, getting in fights with other factions, etc) but the game opens up a lot more when you're pitted against human opponents. It also gets a lot more into the base building/base defense part of the game, where you can build guard towers along the edges of settlements to better protect them. And the decision to strike colors and go pirate.
Yes, in Windward, you can strike your colors and go rogue, hunting down your former faction mates and plundering towns to your heart's content. You have a time limit before you're able to, of course, but it creates interesting new political moves, as you can plunder opposing factions' settlements to destroy their influence and then raise colors and claim them for your own faction. There's an interesting bit of strategy to controlling the regions that I really appreciated for the most part, as it made a game about moving a ship from place to place a lot bigger and more interesting.
Granted, the multiplayer also includes the same jackasses in every multiplayer game, including those who spend their time posturing about how they can "change this whole region pirate", but it's a lot of fun to drift along for a while, constructing guard towers and occasionally butting heads with rival factions.
While it may not be the best game of its type, I fully recommend you give Windward a try. At the very least, it allows for a lot of very deep, but easy to learn, gameplay. At the most, you'll find yourself drawn in to a surprisingly relaxing game of pillaging. While it may not be as deep as others on the market (see also: Pirates), it's well worth looking at.
Final Score: 4/5
Full Disclosure: I received a Steam key to do this review.