The animation rate and the number of frames are now controlled entirely by hires.txt. You may make as many frames as you wish and set their rate.
An example is attached below:https://yadi.sk/d/V5nkHKuyLsvmqA
There you have 5 different frames. Each frame is being displayed for a period of 5 video fields:
If you want to make the running animation faster, you change the numbers. For example to make each frame last 4 video fields, you write:
In the above example the entire animation cycle of 5 frames will last for 4*5 = 20 video fields.
You may make Samus run even faster like this:
But to my taste this is ridiculously fast.
I have not tried it yet, but I think I'm able to modify the footstep sound rate via mmm.ips
You may set up the desired animation rate via hires.txt, and then I'll try to adjust the sound.