And no pedals, also no animation on Firefox.

For me:

Firefox: No feet, no animation

Chrome: Feet included, animated very nicely (uses significant CPU)

What browser are you using that doesn't have feet (or animations)? Seems to all be there in Chrome.

Same happened to me (the feet are on the top left corner, brw). But the generated MP4 works.

For me it worked on Chrome but not on Firefox

I see both feet and animation.