This is not exactly what you're looking for but it might do the job for you...if you can keep from laughing as I explain it.

This assumes the use of Motion Paths for animations that move the players around the slides.

Have the Selection Pane and Custom Animation Pane open. Make sure the "players" are labeled clearly in the Selection Pane on the first slide in which they appear so you'll be able to follow them in the Animation Pane.

The steps:

• Create the Motion Paths for the players on slide 1.
• Duplicate the slide...which creates slide 2.
• Right-click the visible Motion Paths in slide 2 and select "Reverse Path Direction." This makes the ending point of the last slide's player moves the starting point on the current slide.
• Hover over the end point of the Motion Path (so you get the diagonal double-sided arrow...not the four-sided arrow) and drag it to the desired new end point.
• Important...make sure you set the animations to start either "With Previous" or "After Previous" and adjust timings if needed.
• Repeat these steps to create more slides and movements...each one building on the last.

Notes:

• You don't have to even move the players on the actual slide...just the start and end points of the Motion Paths.
• Any slide you view outside of Slideshow view would show the players forever in their original positions.
• You could move the players on the individual slides just to have them closer to their new starting points. This would make the slides a bit more accurate when viewing outside of Slideshow view...but move the Motion Paths as described first to make sure they're accurately placed.

Here are the keys to playback:

• Because the animations are set to "With..." or "After Previous", don't advance the slide until you're ready to show the next player move. You have to do it this way because if you have the animations set to "On Click", the players will always display in their original positions each time you advance to the next slide...rather than being at their new starting locations. Then, only when you "click" would the player jump to his new starting point, and proceed with the animation from there.
• Moving backwards in Slideshow view will mess up the continuity of the Motion Paths since the players will then appear in whatever position they're actually in on the slide...not at the end point of the last animation.

I really hope that helps...good luck.
George