Well, this was one of my more successful bots. It was when I was going to the University of New Mexico c.1990s  I would take engineering and art classes, and I made several projects incoprating aspects from both.  It certainly wasn't a very complex system.  Control was provided by a RC controller, car battery for power, and a gear motor drove a sprocket and chain from bicycle parts.  The study of motion was really enjoyable.  By creating the project I came to the understanding the hip tilts upwards when you begin a step. I used an aluminum slot in the internal skeleton to simulate this.  The upper leg lifts up and the calf pivots as the knee swings forward.  This is the "controlled falling" part of walking.  Once the foot has swung forward the hip, knee, and leg can drop quickly - gravity is ready to assist.  I got this action with a cam which you can see snapping as each step is dropped into place rotating on the bicycle gear.

This is what you can do with a thrown away can opener and some Raku clay sculpture of baby parts.  Yeah, it fell apart, but I like that aspect (delicate mayfly).  The ending of the video was the result of the VHS tape being stored to long in a wet basement, but it seems apropos.

And this was a small art installation circa 1990 which aspired to model some of the aspects of Subsumption Architecture.  Subsumption Architecture is a behavioral inspired AI and popularized by Michael Brooks at MIT.  The gist is that in your intelligence, you have a set of competing behaviors which struggle for control.  The resultant system become more complex than the set of smaller parts.  This concept has always interested me, similar are Conways game of life.  Where very simple rules in an environment can create extremely complex organisms. Fractals also follow some of the same concepts.  Where a set of simple iterated rules generate complex designs.