This movie contains examples of the following tropes:
Actor Allusion: the Buster Hercules transforms into MagiKing, prompting Jin to comment that he feels familiar being inside it.
He even does the Magiranger hand pose!
Back from the Dead: Basco and Damaras, though technically they are Avatar replicas.
Call Forward: The other Kyoryugers arriving late to assist Kyoryu Red addresses the fact that, in the first few episodes, the team isn't open to one another.
Jerashid appears once again, this time in the Edo period of Japan. And no, it's not a past version of him, as he's still wearing his wedding ring. Best not to question how and why he got there.
Also stuck in the Edo period with no way to get back, Yoko, J, and Gai wonder how they can send a message to their allies in the present. J has the idea of writing a message to them, but Yoko asks the obvious question: Who could they trust to hold onto such a message for over 250 years? Gai then gets an idea. Cut to the present time, and Shiba Kaoru personally delivers that very message to the Go-busters' HQ.
Continuity Nod: The background music playing when Gokai-Oh spawns the Megazord Keys, thus heralding the brief return of some past Super Sentai mechas, is the exact same one used in Gokaiger Goseiger Super Sentai 199 Hero Great Battle when the 33 previous main mechas returned.
Early-Bird Cameo: Like its predecessors, this movie marks the debut of the next Sentai team, Zyuden Sentai Kyoryuger, where they take on Waredonaiyer and some Zangyack grunts. This is notable for being the first early-bird cameo to take place inside a warehouse, as the previous three all took place out in the open.
It's also the first where a member of the cameo team meets with the two starring teams, as Kyoryu Red meets his two predecessors before his team's cameo proper start (the other members were late).
Let's You and Him Fight: The Go-Busters fight the Gokaigers, who have seemingly joined forces with the new Zangyack.
Mythology Gag: the whole point of the mechas transforming into other mecha.
Gokai-Oh -> Daibouken: the Boukengers are the Gokaigers' predecessors as the anniversary team, and both series have an adventure theme.
Marvelous even imitates Akashi by snapping his fingers and saying Attack!
GoZyuJin -> DaiZyuZin: the Zyuranger Greater Power is one of the components of GoZyuJin.
Go-Buster Ace -> Gekitouja,Flash King and Ryuuseioh: All the Mechs are fast and agile. Gekitouja is composed of wild felines (even with a red one to boot), while Ryuuseioh is a red mech with his own robot form like Ace.
Go-Buster Lioh -> GaoKing and Gao Kentaurus: Li-Oh and King have lion mechs as the central component of the combined mode plus Kentaurus was the final mech of the Gaorangers just like Li-Oh.
Trapped in the Past: When Enter finds the last of the Phantom Ranger Keys, they react violently and open up a time portal, sending the Gokaigers, Yoko, J, and Gorisaki into the past with no way to get back.
The Worf Effect: Basco and Damaras are taken down rather quickly by the Gokaigers. Basco is defeated by Marvelous, Joe and Luka as Sun Vulcan while Damaras is defeated by Gai, Don and Ahim as Shurikenger and the Gouraigers.