I think this game has a good concept, but to continue the concept the game must go a long way.
Some of the machines are functional, as well as the cannons (very cool), but some could use better functionality and logic (and some of them are just decorative). The game is also severely lacking documentation, it isn't at all obvious what the player is supposed to do while waiting for a pirate ship to attack, for example. You can also just dig up your whole ship if you want to and you won't suffocate or anything. It looks like an implementation for oxygen generation and player reliance on oxygen was started, along with an airlock, but unfinished. There is not a game finish or goal (other than defending your ship) either, so far.
That said, the window for the game jam was small and I'm sure this mod has far to fly! I will be happy to update my review when that does happen :) I'm also a fan of the textures, which follow the style very well.