Top Notch Game
This game blows away a lot of the other games cranked out by puppy-mill web game companies. This is like metroid, blaster master and megaman all rolled into one, with some cave story tossed in for good measure.
My single complaint is that I wished there was more variety in music. Seemed the same music was playing over and over, and it got repetitious. But, there's so much awesome in this game, I'm not counting off for that. It's a minor gripe.
My single suggestion ... if you make a 3rd game, please make the gun where you can eventually merge the weapon systems. I liked each gun separately, but the whole time I was playing, I couldn't help but think how insanely crazy it could get if you could merge rapid fire + spread + missiles + bounce, sort of how you can do in Super Metroid. Maybe have the player earn combo chips, letting them merge 2 weapons at first, then 3, and finally all 4. That would have done away with the need to spend points on shot speed, b/c the single-fire weapon would have been the "speed" weapon to dump points into for that, while the others would just focus on spread, missile and bouncy.
I know, I know, everyone has suggestions, and it's easy to make suggestions when we're not the ones implementing them. But just my two cents.
Excellent game! Difficulty definitely jumped as it went along.