Scramble City was a 15 minute Japanese cartoon released in 1986 intended to fill the 20 year gap between Season 2 of the The Transformers and the movie, which took place in the far off, distant year of 2005, a wondrous future world of flying cars and plentiful energy. It introduced a few of the major characters who otherwise just suddenly showed up without explanation in and after the movie (although in the case of Metroplex, it was implied in the first few episodes of Season 3 that he was the Autobot city attacked in the opening scenes of the movie, but his transformation cog hadn't been installed yet). American audiences never saw it until recently, when it was released on the 20th Anniversary Edition DVD of the movie.
The design of the transformers themselves looks almost identical to the original American version of the cartoon, but certain things betray its Japanese origins. Certain background details look like Japanese design, Menasor runs with speed lines at one point, and when the Aerialbots form Superion in the first dramatic Gestalt combination, I had flashbacks to Voltron. All it was really missing was the obligatory cute animal mascot. The episode appears to be fan-dubbed, and actually it sounded like it was just one guy trying to do impressions of all the voices.
Scramble City (known to American audiences as Metroplex) was the codename for the new Autobot weapon, a massive factory able to transform into a mobile battle mode. Its construction was supervised by Ultra Magnus in top secret, but the Decepticons detect unusual energy readings from the effort and send Soundwave's cassettes to investigate. Blaster's cassettes are unable to stop them from reporting in to Megatron, and the battle is on.
Completely ignored in the standard run of the cartoon was the fact that the Autobot and Decepticon Gestalt toys (with the exception of Devastator) had fully interchangeable arms and legs. Any of the team members (except the one who formed the torso) could switch positions with any other to form any arm or leg. In fact, they were even interchangeable across teams. In a fight between Superion and Menasor, Breakdown of the Stunticons (at least I think it was Breakdown, a later animation error showed that he was still part of Menasor and another source claimed it was Wildrider) was able to join with Superion as the right leg to cripple him.
Although this is the central plot element of Scramble City, it's easy to miss that this is happening unless you're watching for it. Aside from a slight change of color, the Aerialbot and Stunticon limb robots look pretty much identical to each other, and it's easy to ignore this as the standard animation errors that the first incarnation of The Transformers was so infamous for. What's even more difficult is to understand why it's happening. Although Superion and Menasor alter configurations several times in their fight, the specific combination of arms and legs doesn't seem to have any effect on the abilities of the Gestalt.
It's not surprising that something so pointlessly confusing was ignored in the regular run of the series†. The ability of the Gestalts to separate and re-combine is shown to come in handy though, for example at one point when Menasor has Superion in a full nelson while Bruticus is whaling on him, he is able to escape by separating. It's interesting to note that Bruticus and Defensor do not form different combinations, probably because their vehicles look different enough that animating this would be more involved than just re-coloring their limbs.
† However this ability would have come in handy during a Season 3 episode in which First Aid of the Protectobots quit the team, leaving Defensor without a right arm. One of the Aerialbots (who were in the episode but did not form Superion) could have filled in for him.
Following a tradition started by Devestator, it's clear that the Gestalts are in a class of their own. No regular transformer can stand against a Gestalt except under special circumstances, so a battle is often determined by which Gestalt wins a fight. Scramble City was intended to tilt the odds back in favor of the Autobots, and he is completed and ready for battle during a Mexican standoff between Superion, Defensor, Menasor, and Bruticus. With Scramble City towering over even the huge Gestalts, it seems the Autobots are going to win the day, but from the ocean emerges Trypticon, the Decepticon answer to Scramble City.
And that's where the show ends, with Scramble City and Trypticon staring each other down. Rumor has it that there was supposed to be a follow-up episode, but I'm skeptical. What would happen except a big battle between the four Gestalts and the two cities? There is no foreshadowing unresolved, no loose ends to tie up, no new concepts to mark as selling points for the toys, the point had obviously been made. What this boils down to is a 15-minute commercial for the new Transformers cities, the biggest (and most expensive) toys Hasbro had released at the time. Regardless, it is an entertaining 15 minutes if you can find it on line, and I'd still recommend it for fans of the original series.