Really polished look and feel! The only aspects I could potentially point out are design related, such as spawning enemies behind the player's ship even though there is no powerup that allows shooting backwards. Also, while it seemed weird at first to have a regenerating life system similar to something out of an fps, I feel like there could be potentially some interesting ideas to be explored around it, such as allowing life to regenerate faster if the shooting button is not being pressed. That said, I really appreciate the fact that the life bar changes color, making it really easy to gauge the ships current state at a glance.
Anyway, ramblings aside, really looking forward to play a more developed version of this game!