I had to comment as this game is just stunning on every level! I'm a big retro arcade shoot 'em up fan (I collect old arcade cabs and PCBs) and I can't recall the last shoot 'em up to feel like a true 90's arcade classic. You've nailed it on every level. Like the person below, I came here searching for a way of donating money to the project or finding a way of paying for the game but I see you have a Kickstarter coming which is great news indeed. Consider me a backer and someone that will spread the word around!
Good luck with your continued development, I can't wait to see more of this game!