Cartridge code (241 chars):

function r(x,y,a,c)
local w=x+sin(a)*c*6
local z=y-cos(a)*c*6
line(x,y,w,z,k[c])
for i=-1,1 do
 if(c>0)r(w,z,a+i/p,c-1)
end
end
k={11,11,3,3,4}
::★::
for i=0,400 do
i=24576+rnd(8192)
poke(i,peek(i)/7)
end
p=8+sin(t()/6)*5
r(64,96,0,5)
goto ★