Well, It's a start
I like how the fireworks are worth more points the higher up they are when you detonate them, but the point difference is to little. (I got 108 at highest, 102 at lowest. 100 at it's highest, down to 25 at it's lowest would work much better) Give a point multiplier for detonating 2 or more at a time (X2, X3, X4 ect.)
This game NEEDS better graphics for the fireworks. The whole point of the game is the fireworks, they need to stand out for the game to really work. Giving it 5 or 6 defferent 'spreads' would help too. Also the background is too bright, especially the moon. It make it hard to see your reticle.
The size of the game is very small. It needs to be about 50% taller and twice as wide. At this size it looks like one of those cheep 'games' that ad companies use to get you to click on their Ad. And the Tags: cute girls sexy women. I mean, Come on. You've got two static pics that are just there for decoration. They arn't even at the same resolution as the rest of the game.
With just a little work you could have this game up to average quality, something that would make a fun little diversion when you have some time to kill.