Thank you for playing and giving a comprehensive review.
I'm surprised you could beat the boss, there's a bug that happens very often there. I misjudged how much I could do in 4 days, and the actual gameplay - difficulty, maps and the boss - was tossed together in the last two hours. Almost all maps can be played through by standing in the middle and there's no incentive to destroy enemy planes. Next time I'll do better.
At least the explosions in reverse look cool. (Oh yeah, there was a giant explosion at the end of the boss fight as a reward, but at the last minute I accidentally removed it. Oh well.)