I tried your link and it doesn't work for me. I tried shortening and looking through your other stuff and I still coulnd't find it. I seen the tank game you have and it seems to be pretty good. Collision is a little off and so is the bullet shooting. Did you program that in VB because I did something similar, just a little more in depth.(diffrent weapons, powerups, Hud, enemy, AI,Capture the flag, DeathMatch, and online play)
If you want help with the alien birds "flocking" let me see what code you have and give me the sprite images that you want to use.
Psycho Joker