Just one little bug, I found..

Whenever you click on a critter to explode, is the animation all in the button? Because I can keep clicking the explosion until all the particles are gone and every time I click down, I hear the sound effect.

Also, the sound effect plays onPress, but the explosion doesn't take place until onRelease.. so, if I click on a critter, he says "oh no" but doesn't necessarily explode. Wasn't sure if that's how you wanted it to be or not.

Other than that, great job and the background music works just fine for me.