I just were wondering the same and if that's intentional to make it funnier. Because hands seem to stick attached to the body well.

I thought it's by design :)

Reminded me the undead break dance from the inXile's Bard's Tale: https://www.youtube.com/watch?v=sP_7nFldRtY

You're looking at it the wrong way. This Bender features detachable locomotors.

Works on iOS 7 Safari and Chrome for me, but not IE10.

It seems to bring into question the practicality of multi-browser support of these complex 'apps' utilizing fancy CSS and HTML5.

A lot of the neat features used in demo's like this (although I haven't checked this ones code specifically yet) often rely on prefixed features and the like; it's more for showing what could be, rather than what is per se.

Likewise, doesn't work in FF24 on Windows either, nor in IE10.

I am wondering if this works in anything aside from Webkit based browsers.

It works fine, but if let for a while the legs detaches, I thing some variable is offsetting

That's because Bender's metal ass is so shiny.