Awesome game. Significantly better than the first. One little glitch, though. When you move towards the edge of the screen and the battlefield pans in either direction, your shots stay stationary in relation to your ship. I noticed this when I started missing ships because they would pan, but your shots wouldn't.
Again, great game, keep it up!
I like the dynamic of the game. Forcing you to change weapons constantly makes you change your play style. Unfortunately, I feel like the game suffers from a lack of variety. It would do well with more enemy types, or by making the existing types more varied. Different weapons, perhaps in a random order, would make the game more energetic. Overall, it feels like a good foundation, and with a little work could be a great game.