Cartridge code (240 chars):

cls()m=3x=64y=64::★::
for i=0,9 do
w=rnd(128)
z=rnd(128)
pset(w,z,max(pget(w,z)-6,0))
end
p={}
⧗=t()/25
for i=0,m do
add(p,{x=64+sin(i/m+⧗)*64,y=64-cos(i/m+⧗)*64})
end
k=1+flr(rnd(m))
i=p[k]
x=x+.5*(i.x-x)
y=y+.5*(i.y-y)
pset(x,y,14)
goto ★