There was a comment about the noise. It sounded to me like a small motorcycle engine - maybe a 125cc, in which case silencing it would be trivial.
The engine is clearly running at almost constant speed and presumably driving either an electric generator or hydraulic pump which in turn powers the actuators. If it is that kind of engine, and that is the case, then you'd probably get around an hours running (galloping?) time from 5 litres of fuel.
More to the point, however, is that a battlefield capable version would be a lot heavier than this prototype as it'd have to carry armour. That makes me think that a real product would be much bigger... and now think of the psychological effect of seeing a 1/2 tonne mechanical, armoured cat-horse running at you, faster than you can move,, firing its stabilised armament in your direction ("smart ammo", of course)... Might be useful.