Fantastic!
This is a great game. Very good. A couple of things. Try to find more ways to make the filesize smaller. Instead of using bitmaps for skins, try to make cartoons for the faces with vectors. If you press explode at mouse very fast, it kinda freezes, but that is one of the best ways to get a lot of money. Some other characters you could destroy:
Osama
Some more newgrounds characters.
Secret skins.
Make challenges like most damage.
Make things like falling buildings
Those are the things I can think of. I love this game, it's in my favorites list.