RMOS has both a simple game and a paint program, I could see it taking entertaining a child for a few minutes.
It has a calculator and a simple text viewer.
RMOS has a built in desktop, and it can't be modified.
There is a bitmap image for the wallpaper and a config file that you can edit to change the wallpaper.
RMOS is a pretty GUI, that much is for sure. It's also a pretty decent base. It's obvious that it's an early release, unfortunately I don't think we'll ever see a new version.