This game is really fun! It only took me roughly 10 hours to complete. It is never too repetitive and throws a handful of different game mechanics at you to keep things fresh.
There are a number of side objectives you can complete such as: winning all the races, getting every pearl, catching all the looters.
I'm not a huge completionist, so I only tampered a little with the races and such.
The only issue I had with this game was a couple freak camera angles that can get a little annoying.
But, all in all this is a great game and well worth it.