This is a good game! Love art and the sound design. The game here is not upgrading your defenses as it was pretty easy to keep my defenses strong. The game is juggling the batteries. As you are completely defenseless when the batteries are dead. I did feel like it needs some way to upgrade the batteries or unlock another battery, because when you keep increasing fire rate, the batteries deplete faster. And if you just keep the gun going while you recharge the other battery, then you will still lose to missiles. so after a little while it feels unwinnable.