Hi Sarah, great game! I have 3 questions:
1) Did you consider upping health on the enemies to make them scale with the power up?
2) Why is the dual bullet power up so late? And why is it not spreading more and more as it powers up?
3) Do you really need to punish the player with power down on death?
It would be really cool if you could add settings where we can play with these settings and tune them to balance the game to our ability?
Edit: what are the probability of open-sourcing the game after some time? I'm having issues with the collision detection (understandable if you use the hardware collision as it was not intended to use multiplexing) but I would really like to give it a shot!