Very good
This is pretty good. Naturally the concept is king here, with the gunfire creating the rhythm. Is this the most complex rhythm? No. But it's decent. The graphics are the weakness here. It's stick figures first of all, and it doesn't need to be. Albeit, the concept is so strong I voted high on this even when I almost universally give stick animation a zero score. But you could have done a decent animation to go with it and it would not have diminished the concept. Also, the flash is further weakened by the use of repetitive elements. I might suggest trying not to repeat and moving through progressive and complex rhythmic elements. Anyway it's really a one-shot conceptual flash and good job!