Galaxy's End
Once Bowser finally fell, there was a pretty long ending sequence, which in my own mind, I described as "Crisis on Mario Earths". Forgive me if you don't get the reference.
Once the credits began to roll, the kids actually broke into applause. It was as if we had just sat through a long but immensely satisfying movie. Something we started almost a month ago was finally done, and the three of us did every bit of it together.
I might have mentioned earlier about the the second player control as the "star bit collector". Whereas my 4 and 6 year old couldn't possibly do the platform play of player one, they were completely involved as player two. I found the following bit from an interview with Nintendo President Satoru Iwata:
What I originally had in mind, were situations like where a parent would be sitting by their child, and say, the mother would assist her child playing. I also think it would be great if the opposite happens. The mother would control Mario, and her child would assist his mother saying “Mom, there’s a bad guy over here!” A parent and child playing a game as they help each other, was something that I wanted to bring to a reality for a long time, and with Super Mario Galaxy,
I would like to think he succeeded. We had a blast as a family. It's nice to see that Nintendo, as a company, had the forsight to allow so diverse an age range to participate.