One thing - I think the first time I engaged enemies I couldn't switch commands left + right, but the second time it worked fine and I fired some missiles. Mistake on my part?
Even if it was you, it was me.

Even I have a few issues telling if I've selected something or not in the combat screen, which may be what happened there. Alternatively there are a few similarly-named booleans controlling the whole thing, and I have mixed them up at least once before in my code.
That one mission isn't nearly enough, I need more!
It would have been very possible for me to include more than one, but by the time I finished I was just too tired to generate the content that would have been needed. It's a shame, because I put a lot of work into finishing the game's handling of ejected pilots and expended missiles, but there's no way for you to see that it works.

[Good stuff]
Ah, some nice advice there. I've added it to my to-do list.

Ultimately, I'd really like to make the combat much more graphical than it is now, perhaps even with little radar blips circling around shooting at one another. Though that may be a little beyond my abilities, I'm afraid. I definitely agree that the whole combat experience is a little overwhelming and unclear. The chief piece of work on the finished game will be to figure out how to do that well...