Very nice concept but a lot of stuff was a bit unclear during gameplay, what were the barrels for? How far away do I need to be from the whirlpools to not take damage? What is the benefit of engaging in a cannon battle? Does the enemy ship have 10 or 500 health left? Most of this could be easily explained through sound or visually and I think the game would have benefited from that. Other than that, this was great, upgrades both for your ship and for individual islands was really cool :)