The following tropes are associated with this episode:
Bizarro Episode: This episode turns into this when Ash, Dawn, and Barry are transported into a world where the Pokémon are much larger than they are.
Call-Back: This episode actually serves as this as the main plot point: Ash, Dawn, and Barry were taken to an illusion world where they first encountered their respective Pokémon.
Ash with Pikachu when they first encountered the flock of Spearow back in the first episode, “I Choose You!”
Dawn and Piplup when they encountered a group of Ariados and got caught in their web references the episode, “Following a Maiden’s Voyage.”
Chekhov's Gag: Brock runs a Camerupt target booth for the duration of the episode and consistently gets no customers. Until the end of the episode, when hitting the rings of a Camerupt turns out to be the way to escape the tour sequence. Barry even wonders where he got the idea to do that.
A Day in the Limelight: Barry's Heracross is his signature Pokémon for the episode, rather than his usual Empoleon. We also see how they first met, and Barry even has more screentime than Brock in this episode.
Goldfish Scooping Game: The B-plot of the episode revolves around Team Rocket running this variety of game at the festival, though using full-sized Goldeen and giant paper scoopers.. Despite their usual modus operandi and several characters' accusations, it's not actually a scam, and James proves himself to be a bonafide master at it.
Incredible Shrinking Man: Each character is thrown into a flashback of one of their formative moments with their Pokémon, except being considerably smaller than usual.
Put on a Bus: Brock was sidelined in this episode to running a booth and being bored out of his mind while Ash, Dawn, and Barry enjoyed the history tour.
Running Gag: As usual, Barry’s entrance is met with crashing into Ash. He also runs more into people, later Ash, Dawn, and their Pokemon and even into his father, Palmer.
Through His Stomach: It's revealed that Barry attracted and caught his Heracross by slathering honey on a tree.
Throw the Dog a Bone: James actually manages to get a win over the Goldeen scooper master and earns the respect of all of the townsfolk around.
Bizarro Episode: This episode turns into this when Ash, Dawn, and Barry are transported into a world where the Pokémon are much larger than they are.