|Given a second chance to bring Star Trek to life, Gene Roddenberry set out with the self-declared mission to take full advantage of the animated format and create stories that couldn't have been filmed in live-action. Fortunately, he also set out to get qualified writers, bringing back TV writers from the original series (Samuel Peeples, DC Fontana, David Gerrold, Margaret Armen) rather than settle for typical Saturday morning cartoon writers.|
He also brought back popular guest stars from the original series (Mark Lenard, Stanley Adams, Roger C. Carmel).
Fortunately, because despite some beautiful designs, the series fell victim to Filmation's typical budget-cutting animation measures. A relatively limited pool of shots and characters was used, and many continuity glitches occurred as they popped a character head on top of a template body, meaning that Uhura could end up in Nurse Chapel's blue uniform, or McCoy could be wearing Spock's tricorder. The budget for music was equally limited, and and the same musical cues were used over... and over... and over again.
Equally, other than a few big-name guest stars, there was no budget for voice actors. So James Doohan, Majel Barrett, and Nichelle Nichols did dozens of voices of secondary and not so secondary characters.
The quality of the scripts, and the occasionally inspired designs, make up for the low budget. As Roddenberry promised, there were episodes that featured a full Vulcan landscape ("Yesteryear"), giant Tribbles ("More Tribbles, More Troubles"), non-humanoid aliens ("The Infinite Vulcan," "The Survivor"), a dimension of magic ("The Magicks of Megas-Tu"), a dragon ("Once Upon a Planet"), miniaturized crewmen ("The Terratin Incident"), and underwater filming ("The Ambergis Element"). None could have been believably done in live-action.
The series also provided two "alien" crewmen: the tripedal Arex and the felinoid M'Mress. Animation allowed these characters to be fully realized in a way that couldn't have happened in the animated series. Unfortunately, very little was done with them, and Arex served primarily as a replacement for Chekov since the producers couldn't afford to pay for Walter Koenig to join the cast (James Doohan voiced Arex).
The writers also stepped outside of the box on several occasions. "The Slaver Weapon" features the only episode of the five-year mission with no Kirk and no Enterprise. It also introduced Larry Niven's Kzinti for the first and only time in "official" Trek. "The Jihad" featured Kirk leading a team of alien specialists on a Mission: Impossible-style off-world assignment.
Sequels to original series episodes were popular. "Yesteryear", "More Tribbles, More Troubles," "Once Upon a Planet," and "Mudd's Passion" were all direct sequels to live-action episodes, and others featured various elements of the original series, even if they weren't often used to good effect.
Overall, the season fulfilled Roddenberry's promise to keep the series alive.