I'm surprised this isn't Early Access, as it feels incomplete as-is and suffers a few game-breaking bugs. Skills and items, like Ship Repair and Chicken Nests, are obviously not finished/implemented into the game. There are also a few odd design choices that affect the game balance. Certain buffs are able to be applied to all crew members and stack, therefore making the game an odd one where it gets exponentially easier as it goes on. The first island should not feel more difficult than the final boss(es), imo.
Gameplay wise, it's surprisingly similar to FTL. The ship combat and map, at least, have a lot of the same feel. You hire crew (which you have to keep healthy, happy, and fed), and you sail around plundering. There are three location types in the game - islands, towns, and other ships. Within those three, there are a few different flavours (cannibals or hags on islands, big ships or little ships, towns wih differing supplies). With the exception of a few bounty hunter fetch quests, and an option at the beginning to toggle a plague (which I didn't), there are no other events or surprises in the game. It starts to feel remarkably similar after a while, but more content should be on the way. The goal is to beat up progressively tougher opponants for progressively better loot, until you fight the final four bosses (conveniently spread WAY OUT across the huge map). Defeat them, and you get a cute song and the ability to continue playing. I'd suggest watching the cute song on Youtube and buying FTL.
About 14 hours to complete Campaign mode on Beginner settings. I'd say around 3 of those hours (at least) was spent sailing - ie browsing the web in Steam's overlay, and closer to 8 hours if you don't count restarting after bugs/crashes (e.g. reloading caused my first mate to become captain while my captain was still alive, neither could progress).
All that said, it's not a BAD game. I enjoyed it, but have no desire to play it any longer as is. When it's done, it'll probably be a pretty fun open world pirate sim. It definately has charm and personality. Certainly it's not worth the price right now, in Oct 2014. Check it out in a year and see where it's at.