The Curse of Lemmy's Land is a film that takes place in Lemmy's Land
Carmen Cortez, a former agent of the OSS, now works as a private detective but gets little profit for her work. She is contacted by the OSS and informed that her brother, Juni Cortez, is missing. She is reunited with Donnagon Giggles and his wife Francesca Giggles, who explain that Juni was captured by Lemmy Koopa, a villain. Lemmy was imprisoned in cyberspace by the OSS, but he has since created "Lemmy's Land", a virtual reality-based website which he intends on using to escape cyberspace via players that reach the unbeatable Lemmy Koopa. Carmen agrees to venture into the website, save Juni, and shut down the website that is in Bradford City Stadium.
In the game, which takes place in a full 3D environment, Carmen finds the challenges difficult. She finds three beta-testers, Francis, Arnold and Demetra, who launch him to the moon so that they'll have less competition on the way to Level 5. On Roy's Sports Hall, Carmen receives an opportunity to bring in a fellow ally to assist her, selecting his grandmother Helga Avellan (Holland Taylor), who has been looking for Lemmy Koopa for years. She receives a power-up which gives her a robotic suit allowing him to walk. Carmen ventures into a robot battle arena where she fights a boy named Rez in order to return to Earth and Iggy's Casino. She meets the beta-testers again who believe he is The Guy who can beat Level 5. Demetra is unconvinced and challenges Carmen to a race involving a multitude of different vehicles. Carmen wins the race with help from Helga, and Rez joins the group, he and Carmen display romantic feelings for each other. Arnold and Carmen are forced to battle each other in Wendy's Phonebooth, the loser getting an immediate game ober. Rez swaps places with Carmen and is defeated, seemingly getting a game ober, much to Carmen's fear.
The group get to King Koopa's Item Chest where Carmen finds Juni, released by Lemmy Koopa, who leads the group on. Carmen follows a map given to her by Rez to a lava-filled gorge. Because of a run in with Lemmy's Super Koopas, the group surf their way through the lava but Francesca attempts to prevent them from reaching Level 5 to save them, but this fails, for it turned out that the lava was actually cold. Outside the door to Level 5, the real "Guy" appears and opens the door only to get a game ober by an electrical shock. Rez appears, claiming to have got back into the game via a glitch but Juni identifies her as The Deceiver, a program used to fool players. Rez confirms this and apologizes to Carmen. Lemmy Koopa attacks the group with giant robot, Rez shedding a tear and shutting the website down so Carmen and the others can return to reality. However, it is revealed that Helga released Lemmy Koopa, the villain's army of Koopalings attacking a nearby city.
Juni and Carmen summon their family members: Parents Gregorio and Ingrid, Gregorio's brother Machete, their Gramps, and Uncle Felix. With too many robots to handle, Juni calls out to their "extended" family, summoning characters from the first two films (including Fegan Floop and Alexander Minion, Dinky Winks and his son, scientist Romero, and former rivals Gary and Gerti Giggles). The robots are destroyed except the Toymaker's. Helga confronts Lemmy Koopa and reveals that it was he who put him in the wheelchair in addition to everything else, but forgives Lemmy Koopa for his actions, which is why he was perching on his shoulders all those years. Lemmy Koopa shuts down his robot and joins the rest of the Cortez family and their friends to round up a party.