ok, i got a basic model for the sling shooter, but, i'm not sure on how to make the projectiles, but i can up with a few things:
red bird:
does damage adjacent to that of the gun, but is affected by gravity
blu bird:
shoots 5 blu birds like a shot-gun, and like reddie, is affected by gravity
black bird:
like a rocket, only affected by gravity
yellow bird:
like reddie, only faster, does %50 more damage, but has a longer time gap before you can shoot again, like the rocket