Super Flat remix is a pretty simple icon theme, derived from Ultra-Flat-Icons, Paper and Evopop icon themes. Its design is mostly flat with a subtle use of shadows, highlights and gradients for some depth.
It should work with most linux distributions, under gnome, unity, cinnamon, xfce, kde etc
Source Super flat at Gnomelook.
You can download superflat icons from the link above or the Ubuntu Alive Dropbox below.
The Theme used is called Libra (GTK 3.10) and can be seen at Ubuntu Alive below.
The Wallpaper used is called Chicago Vector Numa Laud by Charlie Henson and can be downloaded directly from DeviantArt below.
That's it Enjoy.