gistfile1.lua

function bullet:enterFrame(e)
	if ( self:isOut() ) then
		self:destroy();
	end
	
	...
		
	self:checkCollision()
end
	
function bullet:checkCollision()
	if (#worms > 0) then
		for key, worm in pairs( worms ) do
			local distance = utils.getDistance( self.x, self.y, worm.x, worm.y )
			if ( distance < (24 * worm.xScale / 2 + self.width) ) then
				self:destroy()
				worm:kill();
			end
		end
	end
end

function bullet:destroy()
	Runtime:removeEventListener("enterFrame", self)	
	self:removeSelf();
end