New game:Bunker defense beta version

https://snap.berkeley.edu/project?username=aw8798&projectname=bunker%20defense%20%28beta%20version%29

in the game there a plane they flys touwrds a Bunker and bombs It and your a fighter that Has to shoot it down. however if you down the bomber while moving it spawn multiple and I cant figure out why. can someone help me figure it out?game link

if you only want one at a time then why use clones?

idk I made this a long time ago

idk what I was thinking when I coded it