How Do Animations Work?

[Herotu]

I'm really curious about the animations. I play other games and they're really reluctant to add new animations too, presumably due to the difficulty and time investment required.

 

I would very much like to know;

 

What file type are the animations? I guess they're non-standard because they're so old?

and

Although animations themselves might be difficult to change, would it be possible to change the speed of a selected section of an animation?