Not bad, but I would have liked to see some indication about how much progress you're making against the boss. Also, are you supposed to shoot through the doors that open? I tried to fly into them, but you can't go that far up the screen.
To win the bossbattle, you indeed need to shoot through the doors, Here the boss will take damage, the 2 corses will get red based on damage done. I thought it was quite self explanatory, but maybe that's just because I made it.
