Elementary Viper Luna Gnome Shell theme is inspired by DanRabit's work on Elementary Luna desktop. The theme is created by justviper who in past gave us couple of nice Gnome Shell themes.
The themes looks really similar to Elementary's Pantheon Shell and the launcher at side closely resembles Plank dock.
- Backup /usr/share/gnome-shell/theme folder
- Extract the archive and rename gnome-shell to theme
- Copy this folder to /usr/share/gnome-shell/
- Restart Gnome Shell by hitting Alt+F2, then type r and press enter
- You can also extract the theme to .themes and use gnome-tweak-tool to change themes