I understand that pressing the backspace key will go backward one slide, and
pressing the spacebar will advance one slide. However, when you add animation
to a particular slide, pressing these two keys will "rewind" the slide to the
beginning and "replay" it.
So ultimately, I want a button in the presentation that says "REPLAY". When
users see the slide in presentation mode, they watch the animation. And by
clicking "REPLAY", the user can "rewind" the slide to the beginning and
"replay" it.
You could, I think, put a duplicate of the current slide immediately prior to it,
remove all animations and all shapes that will animate on. In other words, create
a new slide that looks just like the *real* slide when it first appears.
Then set it to transition automatically to the next slide after 0 delay.
On your *real* slide, put a back button or a link to the previous slide.
When the user clicks the link, it'll back up one slide, advance immediately to the
next slide (because of the immediate transition) and since it's transitioning to a
slide that looks exactly like it, there'll be no visible transition at all.
And the animations will reset.
And it'll work w/o macros, so it works in the viewer and in PPT installations where
macros are locked out.