Not very fun, but well made
All the technical aspects of the game where pretty good, at least as much as you can expect from a flash game. It was fairly extensive, and while I'd like to knock the boarding "numbers go down" system, I have to admit I've seen recent commercial games with the same, so I guess I can't fault it too badly.
Unfortunately, while it is technically quite a good game, it was at least for me not very fun. It was pretty slow, and I just ... didn't really have very much control over things. There wheren't any options to make the ship faster/stronger/more agile, or having allies, or anything else to give me an option other than slowly circling with the enemy ship while we shoot eachother. Boarding was entirely interaction free.
I dunno, I'd just personally want more to a battle than holding up and left and pressing z whenever the meter was full, until either one of the ships is destroyed or I can ram it. The ability to aim, or outmaneuver, or coordinate attacks between ships, or upgrade different sections of the ship, or something... and definitely some way to interact when attacking with infantry. Select attack patterns, different weapons that work better against different things, heck, make it rhythm based for all I care. Just something to do rather than watch the computer roll dice for a while. Maybe mystical sea powers to start whirlpools around enemy ships, cast fog, summon sea creatures? I dunno, something for me to do while I watch ships sail in circles and numbers go down...