One of the things that most people complain about (and no one can blame them) is the excessive lack of compatibility between Gnome Shell versions.
Every time a new version is out, the Shell extensions must be updated to work properly, the themes must be reworked and fixed to look as intended etc. Because not everyone is willing to do this every few months or doesn’t have the free time or the appetite to bother anymore, we see many great extensions and themes that aren’t available in 3.4.
Faience by Tiheum
This is one of the simplest beautiful Gnome Shell themes that I ever used. I remember using this on Fedora 16 for at least 3 months before I finally changed it!
Unfortunately, Tiheum didn’t have the time to update this elegant theme and we couldn’t use it under Gnome Shell 3.4 till Erabong decided to do it by himself. So he ported the theme to Gnome 3.4 and we can now fully enjoy it once again!
Elegant Brit by grvrulz
This is a magnificent Gnome Shell theme that looks modern and is fun to use.
Elegant Brit was never updated by grvrulz to work under Gnome Shell 3.6 but a fix was released by Xukashi. The fix concerns only the GS theme and not the gtk so you will have to combine this with something else. I suggest the Miui gtk theme that was released a few days ago.
A New Start by Alecive
This theme is maybe the most unique creation that Gnome Shell 3.2 could wear. It is a “happy” and very beautiful Gnome Shell and Gtk theme that would give a breath of fresh air to your desktop and your eyes.
Unfortunately, this doesn’t end good for 3.4 users after all. Alecive didn’t update it and there wasn’t anyone else out there to bring this fantastic theme to our monitors again. The good news is that the artist confirms that “A New Start” will be updated for Gnome 3.6!