I agree that these games make it more fun, I did that later with in-laws..
The decoration part was already long done before Christmas, in Holland we already put up the tree in November or early December :)
Also, if you are an only child, and left with all adults a whole day who are all having fun and some drinks until late, it's not that fun to be the only child is my experience. My niece and nephew were all long gone to the next family gathering while I stayed behind..
It's important that adults understand that these days aren't fun for children this way..
You're right. I think I was very lucky because I have 4 siblings and a lot of cousins around my age. My family has always been very numerous.