Here's something new, at least to me. Flash characters superimposed on real-world scenes. You shoot them with your finger and a left mouse click. (Hey, if they can invade my world, my finger can be a gun. It's only fair.)
The picture shows what's coming at you after your second kill. Suffice it to say that things get a bit hectic after that. It took me about ten tries to get the screencap.
Warning: Music and sound effects, which you can mute with the M and A keys, respectively.