I haven't had a baby shower, and don't see it happening for me, but one idea I have come across, which is not a game, but gifts from the guests... Each guest brings the gift of a book which they treasured as a child and writes why they enjoyed it in the front as a gift for the baby when they are a bit older/for parents to read to bubs.
I like the idea of the white singlets and fabric paint too. That's great.