Feature request: Play Animations in Reverse

Let us play animations, at least 3D animations, in reverse.

I created a project where I had an object I wanted the user to tap to open, and then they could subsequently tap to close. To my dismay, there was no way to play the animation in reverse. Instead, I had to get creative and imported a new 3D object with the reverse animation, align the two models, and had to hide/show between the two to get the effect I needed.

For practical applications where a user would want to show off an object that can be exploded to show detail but also combined again (the same animation reversed) to show the final product, being able to reverse animations would make the designing process in Aero so much easier.