1. So, first thing, this game is pretty difficult! Unless you just let 2 planets explode and focus on one lane, and then it's really easy.
2. There's no line in the rules to tell the player to move the first set of enemies into Zone 1. I assumed I could attack the decks on the first turn- maybe that was correct? CAN you attack the decks? That seems fine, if so, but then later the rules say that you move "remaining" enemies. If the enemies on the deck are "remaining" then the note about Zone 1 being empty after movement are false, and you don't need a separate step to move enemies off the deck. And if enemies on the deck are not "remaining" then there are no enemies in the field until turn 2. Any of these scenarios is fine, it just needs to be clear which is intended.
3. I was going to say all the enemy ships should be facing down, but then I realized what I had taken for cockpits was actually drive flames, and they are, in fact, all facing down, so... well done.
4. The counter bar divisions should be clearer, I had to squint sometimes to see how many pips each one has. Partly that could be due to the scaling, and partly because my eyes are old, but it would be pretty easy to just make them clearer.
5. It was not immediately clear that I could target *any* enemy in a column, until I read the text on an Astrolith card, and then doublechecked the rules. As it was, I still forgot I could do it and that probably made the game more difficult for me.
6. 4.B says the enemies shoot the card directly beneath them- which would seem to imply they are shooting their own in the back? I assumed this was not the case, but it could be clearer.
7. Needs more pickups. Astroliths should drop heals that restore 1 life to your ship. Or grant a shield- like if you have it in your hand during enemy attack phase you can discard it to ignore 1 damage.
8. I kinda want a way to get junk ammo cards out of my deck, but maybe that's not desirable? Maybe I have to discard an ammo card to purge another ammo card?
9. Game should end if ANY planet is destroyed, but player should get more lives, or at least more options. I think making the Astrolith pickup a shield or heal makes defending an at-risk planet with your ship a more viable tactic.
The art is great, and I dig the theme. I'm working on a similar game, I'll try to get some playtesting done at Forge Midwest this month and hopefully I'll have more ideas to share.