I feel like at some point that the ⌘-backtick (Move Focus to Next Window) worked across spaces when using TotalSpaces.
My research is coming up saying that with the standard spaces, this only works within the same space. If there is some way to be able to move between application windows in different spaces with TotalSpaces that would be great.
Here’s the best info I could find with a quick google search: http://superuser.com/questions/299241/in-mac-os-what-is-the-keyboard-shortcut-to-switch-between-windows-of-the-same-a
As far as I know, TotalSpaces and Spaces in general have never worked this way, but I agree it could be handy, especially if the Space switch transition is really fast.
And just to clarify, I imagine this only working windows of a single app.
Hyperswitch will accomplish what you want. It’s listed as “beta” software (and has been for years), but I’ve never had any trouble with it. I have one keystroke set to “show all apps on the current space” and another for “show all windows for the current app across all spaces”. This is of course in addition to the stock CMD-TAB functionality (“all apps across all spaces”) which Hyperswitch enhances with little preview windows for each app. Pretty neat-o.