You could repair the position of the energy ball launched be the evil nyan.
Doing this and adding some sounds(Pick from games you have) and adding a "you won" message on the end you could have a nice mini-game to begin with.
Also put a bigger background...
PS:Take a look at Shoothing AS Tutorial,you could learn a lot,expecialy if you download the source game so you can lern how it's done.
 "Nyan Attack"){kind=icon}