Well I'm horrible at it!!!! But that's not your fault. The idea is nice, but the art style is not to my taste.
Couple of suggestions:
1. Start with a lower speed for the objects, but keep ramping it up the longer the game goes on. That should be fun imo, a "see how long you can last" kind of situation.
2. Add some more powerups/powerdowns. For example you could add a powerup object that, if you manage to wack it, it will reverse the movement of the objects for a bit, thus giving you another chance to destroy some of the ones you missed. Another powerup could be a "bouncy ball" if you hit it starts bouncing between the walls(screen edge) and the other objects, and destroys said objects for you on impact(giving you score and stuff just like if you had destroyed them yourself). etc.
On the final release I'd like to help out with spreading your game. I don't have a lot of twitter followers, only around 200 or so, but I will tweet about your game if you want. So if you do save me somewhere, and when it gets done send me a pm telling me what particular message, hastags and link you would like me to use.
Good luck with your game mate.