With the basic game dynamics working, I started to add animation to the assets.  Blender's glTF exporter makes exporting animations to webGL relatively simple, but there were still plenty of Opportunities For Learning (OFL) to occur.  :)

One challenge with working on a project part-time is the variation in the look and feel of the models created.   I didn't have a good sense of whether I wanted the game to feel realistic or cartoony.  I didn't know if I wanted something that felt modern or pseudo-historical.  That generated a wide variation in the assets I created.  But I finally found some reference images that were close to what I wanted, so I went back and started updating the assets, concentrating on keeping everything consistent.