Okay, if you could target creatures it would be WAAAAY to easy. Because, if you could do that,you can play death, buy some boneyards and viruses, use the virus ability to kill itself, skeletons will summon, skeletons attack other creatures, more skeletons summon, and you can just keep on repeating this until your opponent kills all of them with thunderstorm or creates a shield which deducts damage. This can be stopped with fire though.
Wirdumby (4 spaces below me): Score is calculated like this: Points X Accuracy X Repel Rate. And Points are calculated by angle of shot (The height and longtivity of the shot). If you shoot low, you realise sometimes the multiplier goes to x0 (times zero) sometimes and if it goes up, no more than x5 (times five). Hope this helped. =D