I really like the simple mix between the spread shot and focus beam. It's a lot more engaging than most shmups I've played. Really well polished, great graphics, and I'm glad there's no lives or anything like that because I died like fifty times on level sixteen.
I think the difficulty curve is quite good with how it starts you off easy then eases into the harder levels. For pacing reasons, I think it would be nice to have an easier level right after the tank boss.
Great work!