This looks great! The boss it pretty cool and feels satisfying to kill. The slowness of the red “bomb” projectiles was a great choice. They can become quit the challenge. I like how the power ups bounce around the level, making them a little harder to pickup sometimes. The wave laser is really fun also. It creates a source of hope when things get really hectic!
A few things I think you could improve on. The sound effect for the player laser may be a little too loud. It kind drowns out the other audio. Also the wave laser destroys the player if he collides with it. This is hard to do, but I did discover it by accident. If you are flying forward and get the wave laser pick you then go left or right you will hit it and die. If this was intentional I would be curious to here your thoughts on why it functions this way.
Also, wanted to say I like you “How to Play” screen. Where did you get the button images?