Needs some rebalancing
This Shmup is nearly perfect, but there are some major balancing issues that you need to deal with before it becomes a major contender. First of all is the Spinning Shield. The area damage combined with piercing projectiles and near invincibility make is way stronger than it should be. I went through the entire game powering up nothing but secondary power reduction, making ship combat a joke. Learn the basic pattern and I could beat a boss in less than twenty seconds without taking a single hit. Once I found the safe spot, the final boss was a cakewalk, all because I was able to damage him and negate his bullets at the same time with a single, rechargable weapon.
Money is also an issue. Beyond bosses, nothing really gave enough money compared to the upgrade prices. If you want to make it far in the game, you basicly have to power up a single part to max, and that leaves no points left for anything else.
FInally are the instant kills. Even though they are predictable for the most part, giving nearly all the bosses an instant kill move seems a bit much. I know, in my first point I said it was too easy and now I'm saying it's too hard, but that's the point of balancing.
I know that seems like a lot of negative, but beyond these three things, it's pretty much flawless.