Recently read the Golden Lotus novel. In one of the scene where Ximen Qing's son was born, some officials presented him baby toys in gold and silver. As far as I remember, there are some bangles, rattles (拨浪鼓), jade ornaments and a few other things to 'serve as a plaything for your son'. Though I have no idea whether the portrayal in the novel had any base on the truth or exaggerated.

You may try here or here for some basic information.

There is an article about toys in the palace, unfortunately it's very short.

There are these things like a drum on a stick with a small ball on a string attached to each side. If you hold your palms together with the stick in the middle and rub (as if you're making fire), then the balls strike the drum and make rhythm.

There's crickets and songbirds in golden cages kept as pets.

Boxes that are puzzles. Solving each layer gets you a bit deeper or possibly to other smaller treasures. The final puzzle might reveal a cavity to hide a child's treasure or might play some music.