24 hours of animation, 18 hours of struggling to get it into the right codec...

What I discovered is that, even though they gave the theme only at the start of the 24 hours, there were more things I could have done to prepare. On the technical side, get the right software and the right cables ahead of time. On the artistic side, create the characters ahead of time, and give a few trial runs of the technique to be used.
Overall, this was really good fun. A million thank yous to Laurent, who took the kids to the zoo, into the garden, for naps...