Cartridge code (183 chars):

cls()x=64y=0k=.5n=3
::★::
cls()
for i=0,5000-k*6000 do
o=ceil(rnd(n))/n+k*5
s=128-k*100
x=x+k*(64+sin(o)*s-x)
y=y+k*(64-cos(o)*s-y)
pset(x,y,7)
end
k=sin(t()/10)*.15+.65
flip()
goto ★