Having for the moment escaped the Decepticons by means of the Elaborate Ruse, the autobots in the mostly blown-up spaceship crash-land on the Planet of Junk. Like Quintessa, the Planet of Junk seems like an excuse for the artists to stick in some things they'd been wanting to use -- robots that turn into motorcycles, things with spiky wheels, chaotic backgrounds and general randomness. It's also possible that the Junk planet, inhabited by Junkions, was arranged to be amusing without imparting any new interests to distract from the main characters. Sofar as I know, none of the Junkions had toys made of them. One unusual touch was that the Junkions have facial hair -- which is approximately as superfluous on a robot as RC's breasts.
Back on Quintessa, Hot Rod and Kup encounter one of two species of Sharkticons under the control of the Quintessons. Behaviorally, the Sharkticons are somewhere between ill-behaved preschool children and undertrained dogs. This is, however, the introduction of the Universal Greeting concept, which lodges somewhere in the recesses of the brains of people who see the movie. The Universal Greeting is pronounced "Bah Weep Granah Weep Ninny Bon" (or the last word may be Bah, there's dispute on that point). This is supposed to reduce potential enemies (other than Decepticons) to incredible friendliness and comradely good fellowship. In this scene, it merely delays for a moment the part where the Sharkticons jump on and attempt to eat Hot Rod and Kup. After a minute or two of this the Sharkticons think better of it and take the two off to see the Quintessons, presumably since that's their sole purpose in life anyway.
The popular form of entertainment on Quintessa, at least if you're a Quintesson, is acting as a magistrate over other people's trials, where if you declare them innocent you get to feed them to Sharkticons. The "crimes" alluded to amount approximately to "being at hand." No one is ever found guilty in the movie, so the retribution in that instance isn't explored. Here the Quintessons feed Cradix (the survivor of the planet eaten by Unicron way back in the beginning of the movie) to the Sharkticons. This is intended to be a tragic moment, where the last surviving member of a robotic species is killed off, but it comes in a movie where they're killing off established and beloved characters left and right, so it doesn't have as much effect as might have been intended. Hot Rod and Kup are also found innocent and tossed in with the Sharkticons, but miraculously escape by way of causing the water to overflow, then (with the help of the Dinobots, who arrive just in the Nick of Time) arrange a Sharkticon mutiny which presumably eliminates the Quintessons.
It's also worth noting here that at some point in the TV show it was subtly indicated that the Quintessons were the original creators of the Transformers. If so, there doesn't appear to be much ancestral fellowship to it.prior, post, hence