Advanced Thing: #2 - Complex Behavior - Example: minfig-0 - On top of having a full walking and turning animation, I added a fair bit of logic to make the minifigure be able to traverse a decent bit of the map (not confined to just one corner), without just walking through the houses I put down. So as a result the "AI" does some checking for where it can move. I set this up so that it respects the boundaries of the town plane, as well as to not walk in the center area so as to avoid getting hit by cars (ouch). On top of that, it also does checks to walking through houses, by checking slightly ahead of every movement step it does. This behavior is shared with the Gonk droid although its walking animation is different.

extra (also #2 - complex behavior) - Example: legoLogo-0: To have the lego logo, I added some functionality for the logo pieces to traverse a Bezier curve in 3D space with randomized control points - so that the pieces go from the sort of mess in one stage to being fully assembled and vice versa, while having some degree of randomness in between.
Since it randomly chooses these control points, every time you reload the page it might look slightly different.