Awesome.
The gameplay was challenging, but not too difficult, and some of the encounters featuring multiple ship types were extremely enjoyable, but what really made this game for me was the graphical style. The dark, pessimistic, atmospheric, and beautiful shades of gray and surreally glowing pale yellow was truly awe-inspiring and added so much to the game.
There were only two parts of the game that could easily be improved: the upgrade system, adding more upgrades and perhaps improving the heavy cannon a little, and the main game's music, which didn't match up at all with the music during the intro and outro.