I enjoyed the intro to the game. The scroll, font and sketches all blended together well, suiting the theme of the game perfectly. However, I didn't feel that the buttons blended in too well here. The black and white lines as a border made them feel out of place. The paper sound effect as the pages were turned was a nice touch, but the click sound of the button at the same time meant that there was too many sound effects at once. The buttons' click noise should have been disabled during the intro.
Everything in the game seemed to fit together nicely. The art was well drawn and the sound effects were spot on, as was your choice in music. The gameplay was enjoyable, but given the length of the game it soon became repetitive. There just wasn't enough variety in the quests. All but one involved shooting enemies and this was only the treasure hunting mini-game which was playable through collecting a map from a ship anyway.
Why wasn't pausing the game assigned a key on the keyboard? Since everything else could be done via the keyboard it didn't make sense that something like the p key couldn't be used for this.
I thought that the upgrades were too pricy at the start of the game. It wasn't until after two or three days that I was able to get the first upgrade for my ship. I think that you should have made the cost of the upgrades less by quite a bit, particularly the first ones in each category. Even later in the game after upgrading everything a few times I felt that the prices were too steep as come that point I was getting rather bored of the same old gameplay and didn't really want to play through another two days just to upgrade part of my ship.
I don't think it specified that you only had a set number of moves in the tutorial for the treasure hunting game. Perhaps I should have noticed the spade with the number next to it in the top left corner, but I didn't see this on my first attempt at it, so I think that this tutorial could be updated to inform the player of this.
The AI seemed a little poor at times. Ships were happy just to drive directly in to the side of you, meaning they couldn't fire at you, but you could easy fire at them. They also occasionally seemed to wind up stuck on rocks and didn't make the correct movements to get away from them. I thought that the cannonballs from other ships should have been able to hit other ships as well and also that during the pirate defending mission, your cannonballs should have been able to hit the ship you were supposed to be defending. The defending mission was too easy anyway, as the only enemy ships that appeared were the ones chasing you and they simply left the other pirate alone. Later in the game, pirates would occasionally engage me, only to flee shortly after. I'm not sure if this was intentional or not.
The fort moved far too slowly to be any threat at all. The only threat was the other ships, which were easily taken care of. On the other hand, the damage inflicted by the battering ram ships seemed incredibly harsh, even after a few armour upgrades.
I liked a few of the extras in the game like the seagulls flying overhead and ships that weren't part of the quests. It could have been a nice touch if other ships were battling each other though. I wasn't too fond of the sea graphic layer. It felt a little too cloud-like.
There didn't seem to be any punishment for having your ship destroyed. Even if you lost to the pirates attacking you for a piece of the eye, you were left with all the pieces you'd collected.
I thought that the game could have done with more story instead of just being 'shoot ships, collect eye pieces, upgrade ship'. I can't be sure if you had any come the end of the game, as I didn't complete it. I managed to collect all the pieces of the eye and attempted to beat the kraken a few times, who I thought was far too tough a boss when compared to the enemies you'd been facing throughout the game. However, it was clear that my ship still needed a few improvements and I couldn't be bothered to perform the same tasks again in order to defeat it.