That just seems to move along in little tiny steps. No balance or slip recovery shown. That's the wind-up toy level of walking.[1]

Still, it shouldn't be that hard to make a small version of Big Dog technology now. They put a lot of money into fast hydraulic servos, which you no longer need for anything smaller than a horse. Gyros and accelerometers are cheap now, because they're phone parts. Motors and motor controllers are much better and cheaper now. Big Dog's compute power was a Pentium 4, which is nothing today. Force feedback sensors for the feet are still expensive, because there's no mass market. You need those for slip control.

[1] https://www.walmart.com/ip/Wind-Up-Wooly-Walker/194850858