Cool gameplay, this must have been a somewhat similar view during the kennedy assasination...
I liked the gun sound and ambience and the big variety of characters running around, they are cute.
I think the biggest improvement for me to the game would be to have more user feedback, so more or less bonus if I shoot the target faster, with some sounds and more bling bling. Maybe have somebody ride, run or drive through the park to be a faster target. Maybe you could make it so that you can miss the target when you are to slow or something like that.
At first I thought oh nice... a "where is waldo" style game which i can play with my 6 years old son... but than I was sniping people in the park...
Cool Idea well done.