Played the current version.
Really cool stuff. I actually liked a lot about it
the level of challenge, the presentation (nice to see something different, instead of pixel art..reminds me a little of edmund mc millen's early games..and the music fits really well too), the idea with flappy bird controls is really good also, the enemy types compliment the idea very well.
The only thing that kinda bugged me (but not that bad after a while) is, that i couldn't choose where to shoot to. While playing it came to my mind, that you could actually shoot to the point where you click with the mouse. That would give the player full control over the ship. On the other hand, that could make your game a little too easy, but idk, you could try that out, if you havent already