Frustrating, yet excellent for it.
I refuse to give 10's because nothing is perfect, but for what you were going for, this is very close. The fact that the game provides with no actual advantage over your foes is at once vexing, but extremely refreshing.
If I were to suggest anything, for a sequel (please tell me there's going to be a sequel!), it would be a system to give orders to your NPC ships. Even if it's just "Follow me", "attack X" and "Engage at will" orders, it would be a great help. Right now, four-way (and to a lesser extent, three-way) battles are as much, if not more, a matter of starting position and luck than skill. A rudimentary command system would bring it back towards skill rather than luck, I think.
Secondly, a couple more ship designs would be nice, actually. Some variant designs maybe, rather than simply making ships bigger.
For example, a fighter (or slightly bigger than a fighter) chassis carrying one of the Destroyers repeating lasers, but nothing else. Or a Destroyer variant carrying turreted fighter-style lasers. Just some ideas.