In this wave-based action defense game you are the Captain Woody of a little pirate ship. Consequently he has two wooden legs, but that's not really important - it's a joke like most of the game's story content.
Woody stole some gold from the mighty pirate captain Davy Jones. Unfortunately for Woody, Jones sends his armada of sea monsters and ships commanded by various undead to bring the gold back. You have to sail and cannon away at the enemy ships, which there are maybe ten different types, most of them seemingly little more than re-skins of the basic type, though their behaviour does vary a bit.
It is really an armada: there are tens or even hundreds of ships sailing against you each level. This is alright (Woody doesn't really care for realism) but for the fact that the waves of enemies come from four different directions and the waves don't wait for the previous ones to die before emerging. Depending on your mindset, this is either challenging or just frustrating.
Some of the ships concentrate on attacking you, while others race for stealing the gold and you have to stop them fast because you lose if you run out of gold. Initially I thought dying would be final but soon I realized I only lost a tiny bit of gold as a punishment and the ships steal way more than that, making life count little in your quest for keeping hold of the gold.
Destroyed ships drop power-ups that either benefit or punish you depending on their colour. They contain various weapons from mines to kamikaze dolphins. The webs can be frustrating as they stay in place for a really long time and all the ships, including yours, get stuck in them.
This brings us to the controls: they are wonky at best. You can steer left or right, go two different speeds or stop. You can also shoot to both sides. Steering and moving is the wonky part, because the ship takes a brief moment to register your steering maneuver. Don't get me wrong: this is actually realistic. It just makes the steering a chore, making it tedious to hit the power-ups. The worse part is the two-tiered speed scheme: you either go quite slowly or a bit too fast. Gaben help you if you grab a speed power-up, because it doubles your speed but it will stay two-tiered. Speed bonus is often useful trying to reach the next wave of ships before they reach the island, but it makes it difficult to avoid your own mines and webs and to maneuver into a decent shooting position, deteriorating your attacks into crazy sail-by-shootings where most cannon balls miss their targets.
Levels consist of a single island with your treasure and maybe a reef or two, making them very bland and repetitive. Hitting a reef or the island makes you and enemy ships bounce off of them harmlessly. The same goes for hitting an enemy ship, so unfortunately there are no ramming maneuvers either. Only real differences between levels are the reskins of the enemy ships: three different behaviours with different outlook. It appears that later levels also have more enemy ships. Every level also has a different boss, making it the only thing to wait for. They will probably kill you numerous times before you win them, but what gives, you just respawn to attack them again, slowly grinding their health down.
By the way, in the story mode the gold you lost will stay lost between levels, so you might lose the whole story if you lost too much gold in the early levels. The game is challenging but unfortunately rather boring after a while. The story is silly and recited between levels by a person who sounds either bored or over-dramatic.
All in all, I completed the game in some 5 hours in easy, medium and hard settings but didn't bother with the nightmare, because I had obtained all the achievements by then. It could have been much more interesting with ship and reef collisions, less numerous but more dangerous enemies and outsmartable but challenging bosses - now kraken was the only one who qualified.
I can't really recommend this game but if you get it for really cheap (e.g. in a bundle like I did) you may waste a couple of hours on it. The only thing I liked a bit was the only slightly annoying, jolly tune you listen to while blasting the undead ships.