Man, pretty addictive. I can't tell if I want there to be a stronger tutorial, or if the experience of learning how everything works myself is rewarding enough that a tutorial would take away from the game. This game is incredible though. My only nit pick would be that I had a hull breach I couldn't fix that opened up over the Ziggy spawner. I'd also say that it would be nice if hull breaches maybe released sparks or had some other effect that made them a little easier to see. Also, the sound seemed ok, but the CONSTANT alarm sound going off drove me INSANE and drowned out all of the cute dialogue that I'm sure you worked hard to add. I think you could probably stand to turn that alarm off :/.
That said, this game is practically ready to ship. I'd maybe widen the ship and add multiplayer (which I know is a huge task), but frankly I could see this, as a multiplayer game, being released as is on steam and doing alright. Great job.