this has to be one of my most favorite games on Newgrounds. The difficulty is hard enough so you are challanged and may die, but not enough to make you frustrated. It is quick-paced, so you will never relax until the upgrades screen.
2 things i would like to point out though,
1.as soon as i got 45 on power, i got a triple shot, which made the game easy to the point of moving diagonaly and shooting. try not to make such a big jump in the sequel, if there is going to be one.
2.on lvl 15, i spontanously coumbusted (burst into flames) im guessingh that was the dark blue orbs that people complain of. please don't make their explosions that big, and give them a different color like blue on the outside, green on the inside.
Overall, this actually beat my expectations on flash games. This game deserves somthing better than 10/10, but thats all i can give you.