I made a clone of the space invaders game, but it has a catch, theres another weapon to use, An Ion Cannon, with limited shots, I got the instructions to modify it for v3 arcade at
http://www.v3arcade.com/forums/showthread.php?t=272 and dont have an arcade of my own so dont know if it works, but Hopefully it does :P
Its an attatchement (The last zip didnt have a few things, I just updated it)
P.S. If you use this, and it does work, please tell me, I dont wanna keep wondering... :P