Dear Hans, Aditya,

Now, I understand the stacking method.
I made a simple animation using it.


\startuseMPgraphic{demo}
  for i=1 upto 10:
  draw fullcircle scaled (.3*i*cm)  withcolor (.1*i*red) withpen  pencircle scaled (.5*bp) withstacking i;
  endfor;
\stopuseMPgraphic
\setupinteraction[state=start]
\usemodule[animation]

\starttext
\startanimation[menu=yes]
%  \dorecurse{10}
%  { {\useMPgraphic[stacking={#1}]{demo}}}
  {\useMPgraphic[stacking={1}]{demo}}
  {\useMPgraphic[stacking={2}]{demo}}
  {\useMPgraphic[stacking={3}]{demo}}
  {\useMPgraphic[stacking={4}]{demo}}
  {\useMPgraphic[stacking={5}]{demo}}
  {\useMPgraphic[stacking={6}]{demo}}
  {\useMPgraphic[stacking={7}]{demo}}
  {\useMPgraphic[stacking={8}]{demo}}
  {\useMPgraphic[stacking={9}]{demo}}
  {\useMPgraphic[stacking={10}]{demo}}
\stopanimation
\stoptext


However, I cannot succeed to use \dorecurse to make the code simple.
If there is another good method, please let me know.

Anyway, thanks for this new feature!

Best regards,
Dalyoung