Try harder.
You drew the gun nicely, but that was about it. I was able to see the game move from picture to picture, and it was especially apparent if I watched the figures as they jumped out. The hit detection wasn't that great, and the stick figure would be able to shoot me no matter how fast I shot it, insuring my inevitable defeat. The gunshot sound was repetitive, and began to become annoying after a short amount of time. I reccomend spending more time thinking out your games, adding more frames while increasing the frame to frame speed, and using different sounds to make it less repetitive. I hope my criticism won't discourage you. Please don't give up just yet.