The selection of commercials (below) created at Richard Williams Animation shows the wide range of styles of which the studio was capable. Of particular note in reference to Who framed Roger Rabbit is the Long Life Beer ‘9 Lives’ commercial. It was the zaniness of this commercial that impressed Spielberg and Zemeckis and contributed to them pursuing Richard Williams as Director of Animation.
Also, you can see in the Kellogg’s Tony the Tiger ads and Fanta ads (with Disney characters) that Richard Williams Animation was already far along the path of the 2.5-D animation that made Who framed Roger Rabbit stand out.