Mungo Baobab, C-3PO and R2-D2 make their way for the planet Roon, but Governor Koong's drone fighters chase after them. Mungo attempts to lose them. However, the drone fighters manage to infict damage on their starship. While R2-D2 attempts to stabilize, C-3PO panics and argues with R2-D2 about bailing out. Mungo crashes his ship on Roon. On the ground, Nilz Yomm and his daughter Auren witness the starship crashing. Nilz sends Auren to investigate.
Meanwhile in space, the droid pilot inform Governor Koong's aide-de-camp Gaff that their mission was a success. A pleased Gaff tells Bun-Dingo to take over the controls while he informs the Governor. Admiral Terrinald Screed is growing impatient with Roong for not delivering on his promise to bring the Roonstones to the Emperor. Koong claims that he has much more to offer the Emperor. Screed is skeptical that a desolate world like Roon could offer much to the Emperor.
Koong proposes that they compete in the Roon Colonial Games in order to secure the Roonstones from Umboo. Gaff tells Koong that Mungo has been destroyed. While Koong is jubilant, Screed remains less than impressed and reminds Koong that he is only Governor of Tawntoom province. Koong claims that he runs the entire planet except for Umboo. Koong vows to crush Umboo's champions during the Games. Despite his disdain for Koong, Screed decides to give Koong a change to control Umboo at the Roon Games. Koong orders Gaff to set a course for the Roon Games.
Meanwhile, C-3PO, R2-D2 and Mungo climb out of their crashed starship. C-3PO falls from the top of the ship and lands on the mud. However, he is grabbed by a giant Mudman. A second Mudman jumps over R2-D2's dome. Mungo sees more Mudmen on top of his starship. Mungo attempts to help C-3PO by attacking the Mudman but it splits into three more Mudmen.
Just then, Auren arrives on her rockhopper and disperses the Mudmen using Artoo's water pump. After driving away the Mudmen, Auren explains to the offworlders that the Mudmen are harmless and just love shiny metal objects like droids. Mungo disagrees and points to the damage to his starship. Auren responds that she should have just left them. This prompts Mungo to apologize and to thank her for helping them. He introduces himself as Mungo Baobab from the Baobab Merchant Fleet and also introduces R2-D2 and C-3PO.
Auren introduces herself and explains that she and her father Nilz were traveling to the Roon Games when they saw their starship crash. Nilz Yomm soon arrives in his landspeeder and asks Mungo if he had trouble with Governor Koong. Mungo explains that they were prospecting for Roonstones when Koong's drone ships spotted them and gave chase. Auren explains that Governor Koong wants to control everything on Roon but vows that he will never control the free spirit of their home province of Umboo. Auren vows to find a way to defeat Koong.
Nilz offers to take Mungo and the droids to the Roon Games, suggesting that they could find someone to help them repair the ship. Gaff, observing the crash site, realizes that Mungo survived. When Bun-Dingo asks if they should inform Governor Koong, Gand advises against it because he fears that his master will lose favor with Admiral Screed. Gaff resolves to kill Mungo himself. When Bun-Dingo asks about Auren Yomm being Koong's competition, Gaff responds that she "was" his only competition.
Traveling down to Roon, Gaff observes that the Yomms, Mungo and the droids are near a Shamunaar, a giant, ancient hibernating creature. He fires a blaster bolt near the creature's eye, awakening it. This causes the ground near the crash site to quake. Auren thinks this is an earthquake but Nilz points out that it is a Shamunaar, an ancient beast that hibernates for decades. Gaff hopes that unleashing the angry Shamunaar will lead to the deaths of Auren and the others, eliminating Koong's competition.
The giant red, saurian creature scatters the droids, Mungo and the Yomms. Mungo and the droids hide inside crevices and caves. The Shamunaar begins smashing rocks and other structures with its massive tail. Nilz is pessimistic but Auren believes that they can still defeat the beast. She rides her rockhopper and charges to face the creature. C-3PO and R2-D2 huddle in fear while Auren rides her rockhopper under the creature's legs. The Shamunaar causes her to fall off her mount. Mungo tells the droids they have to draw the beast away from Auren.
Mungo rides the rockhopper while C-3PO and R2-D2 taunt the beast. Mungo manages to rescue Auren and they lead the Shamunaar on a chase. R2-D2 jabbers at the beast in binary until Mungo tells them to flee. Nilz picks up the droids in his landspeeder, with R2-D2 riding with a grappling hook. Having failed to capture its prey, the exhausted Shamunaar goes back to sleep. Nilz is relieved they have tired out the creature. C-3PO tells his master Mungo that he is relieved he survived. Mungo gives credit to Auren and Nilz. Impressed with Mungo's riding skills, Auren suggests that he compete in the Roon Games against .
Accepting Auren's invitation, Mungo tells R2-D2 an C-3PO that they are heading for the Roon Games and glory. Before leaving, R2-D2 captures a Mudman that attempts to cling on to him. As they travel to the Roon Games, C-3PO remarks that he has experienced all the glory that he can handle for the next millennium.
The group travel to a stadium where the Roon Games are being held. Droids prepare the stadium while a green alien and blue tentacled alien announce the contestants. The first event is the Drainsweeper Race. From their upper suite, Admiral Screed tells Governor Koong that the Emperor would have enjoyed these games provided he always won. Governor Koong tries to flatter Screed by describing the Emperor as a man after his own heart. Screed reminds him that Koong's team has yet to compete with the Umboo Rebel champions in the final event.
The green alien announcer announces that if Auren Yomm and her team fail to turn up, Governor Koong's team wins by default. To Screed's dismay, he discovers Baobab has survived the crash. Koong is horrified and chokes on his food. The television shows footage of Auren Yomm and her Umboo riders as well as Baobab. The announcer mentions that Gee Long and the droid BIX have won the Drainsweeper event for three consecutive years. He explains that they are the only team who have managed to hold out against Governor Koong and his ruthless Tawntoom team.
Screed warns that his Emperor dislikes allies who lose while Koong warns Gaff that he cannot afford anymore mistakes. He orders Gaff to destroy his rivals. Gaff responds that he has already set a plan in motion against the Umboo team. He says that Baobab is his.
Meanwhile at their tent, Artoo has adopted a pet Mudman while C-3PO rests his legs. Mungo tells the droids that the crowd loved BIX and Gee Long, two members of Auren's racing team. Mungo thinks that they should take advantage of their free time to track down a repair crew for the cloud car. Unknown to them, Bun-Dingo is spying on them. As they leave, Bun Dingo steals Artoo's pet Mudman. R2-D2 attacks the larger droid but is brushed aside. Artoo catches Bun-Dingo sabotaging BIX by unplugging him while he is being charged. Bun-Dingo also pours droid coolant into the Mupple juice supply. Gee Long drinks the contaminated liquid and convulses in pain.
Elsewhere, C-3PO serves Mungo some Mupple juice. A distressed R2-D2 arrives to warn them that they are in danger. Just then, Gaff attacks Mungo from behind, leaving him with a poisonous scratch. Back at the tent, Mungo awakes with C-3PO and Nilz inside the tent. Nilz explained that he had a run-in with Koong's henchman Gaff. Auren attends to the ill Gee Long, who is unable to race due to food poisoning. R2-D2 drains the droid coolant from the Mupple juice supply. BIX is also unable to recharge until the next race.
With the Drainsweeper Race approaching, C-3PO suggests another droid but is reluctant to volunteer himself. He suggests R2-D2 but the droid is preoccupied with Gee Long and beeps back in binary. The alien announcer announces that Umboo can still win the games if they can defeat Tawntoom in the Drainsweeper Race. Gaff is confident that the Tawntoom team will win due to his sabotage. However, he is alarmed to see that Mungo and C-3PO have joined the race.
Mungo tells C-3PO that the Drainsweeper Race is a three lap relay. If he can stay in the race, Mungo says that he and Auren will do the rest. C-3PO says he will try his best and hopes that Bun-Dingo doesn't have any surprises for him. R2-D2 wheels away to deal with Bun-Dingo. Koong hopes that the defeat of the Umboo team will allow him to bring the province under his heel. Meanwhile, Bun-Dingo brings the captive Mudman into his laboratory. While Bun-Dingo is distracted, Artoo swipes back the pet Mudman and replaces his turbo coolant with a different one.
Threepio starts the Drawinsweeper Race. Tawntoon takes the lead followed by the . The Galaxeed rider attempts to challenge the Tawntoon champion but the latter knowcks the former into a pit, where an operator uses an artificial gravity generator to ensure a safe landing. Gaff knocks the artificial gravity operator out and takes over, turning the gravity up to ensure a fatal landing.
C-3PO completes the first race safely but in last place. He attempts to pass the baton to Mungo but falls off his rockhopper steed. Mungo catches the baton and mounts the rockhopper. Auren reassures C-3PO he was terrific as does R2-D2. During the second leg, Mungo almost gets knocked off by a tentacled rider but manages to knock the competitor out instead, leaving only Auren and Bun-Dingo to complete the final lap.
Prior to the third leg, Gaff asks Bun-Dingo if he has enough turbo coolant. Bun-Dingo says he has a full tank. Gaff tells Bun-Dingo to push Auren Yomm into the funnel, where he hopes she will fall to her death. Mungo passes the baton to Auren, who rides after Bun-Dingo. He tries to activate the turbo coolant but it begins bubbling instead. Losing control, Bun Dingo falls into the funnel and crashes into the ground, breaking into pieces. The green alien announcer announces that Tawntoon's rider has fallen.
Refusing to concede defeat, Gaff tries to sabotage Auren by shining a bright light in her eyes but Artoo drops the pet Mudman over Gaff's head. Gaff throws of the Mudman but it divides into five smaller Mudmen who carry Gaff away. The alien announcer announces Umboo as the winner of the race once more. Auren dismounts and hugs Mungo.
Elsewhere in the stadium, a displeased Admiral Screed warns Governor Roong that he will no longer be given any chances and demands the Roonstones that were promised to the Galactic Empire. He orders Koong to deliver them to him.
Meanwhile, Auren along with Mungo and C-3PO attend the award ceremony. Having found fans, Auren believes that Mungo will have little trouble finding a repair crew. She says she will miss Mungo and the droids. Mungo replies that they will only leave if they can't find anymore Roonstones. Auren promises Mungo that she'll help him find his own Roonstones. C-3PO gives his medal to R2-D2, believing that he truly deserves the award. He asks R2-D2 to do the riding next time.
"The Roon Games" was released on DVD in 2004 as part of the Treasure of the Hidden Planet feature film.