The ebuild for enemy-territory does not create a link in the Gnome Menu
Steps to Reproduce:
1. emerge enemy-territory
2. look in the menu (after an restart from X)
From line 69 of the enemy-territory-2.56-r2 ebuild:
make_desktop_entry et "Enemy Territory" ET.xpm
That and I have an entry in my Gnome menu after emerging enemy-territory. You probably simply need to emerge sync and try again, though the menu entry has been in enemy-territory for a very long time.
Excuse for my silliness.
It is in my menu too.