I don't know about Roddenberry being upset about the limitations of the program's animation. Keep in mind, there were budget constraints for animated programs, back in 1973. According to the Star Trek: The Animated Series DVD features section, while Filmation was putting the program together, Roddenberry was around to offer his consultation on the program, especially the part when the studio was behind schedule getting the show ready for broadcast. He stepped aside and allowed the studio to continue working on the program without further interruptions, but still returned to offer his insight. It was a complicated process, but with both Paramount and Filmation working together on the program, Gene Roddenberry had to be involved. Walter Koenig did contribute an episode of the animated program to begin his career as a writer, which in a sense compensates for Filmation's limited budget preventing him from contributing to the program as an actor. Only six episodes were made in late 1974, because back then, the program was becoming increasingly expensive to produce. Find out more info about the program by going to your local public library and look up the book, The Encyclopedia of Daytime Television by Wesley Hyatt, published by Billboard Magazine.