Hmm........ In terminal type these

$ sudo add-apt-repository ppa:gnome3-team/gnome3
$ sudo add-apt-repository ppa:gnome3-team/gnome3-staging
$ sudo apt-get update
$ sudo apt-get dist-upgrade$ sudo apt-get update
$ sudo apt-get install bijiben polari gnome-clocks gnome-weather gnome-maps gnome-music gnome-photos gnome-documents gnome-contacts epiphany-browser gnome-sushi gnome-boxes gnome-shell-extensions

then just restart it, login into Gnome Shell, thats it.