Dragon Ball: Plan to Eradicate the Saiyans (サイヤ人絶滅計画, Saiyajin Zetsumetsu Keikaku; lit. "Dragon Ball Z Side Story: Plan to Eradicate the Saiyans") is the fourth installment of the Gokuden series of Famicom games with a completely original plot as opposed to what came before it. It later was adapted into the first Dragon Ball Z OVA as a visual guide to the original game. The OVA was later remade into a shorter but updated bonus movie for Dragon Ball Z: Raging Blast 2.
Dr. Lychee is one of the only survivors of the Tuffles, who were massacred by the coming of the Saiyans in the original anime adaptation. Lychee managed to escape with a capsule and found refuge on the Dark Planet, a world at the end of the universe. Now, his only wish is to eradicate the last remaining Saiyans, using a deadly substance known as "Destron Gas" to slowly destroy all life on planet Earth.
While an Excuse Plot in general, the core ideas and concept were later better explored in Dragon Ball GT, which also includes the Tuffles and a villain who was no better than the Saiyans he so detested, and Dragon Ball Super, where a Tuffle and another warrior who greatly resembles Hatchiyack, Aniraza, appear in the Tournament of Power.
This work contains examples of:
- Adapted Out: The remake cut out a lot of scenes from the original such as taking out the surrounding Destron Gas emitters and the journey to the Dark Planet.
- Advertised Extra: A lot of emphasis is put on Hatchiyack in the marketing rather than Lychee. Justified, since Lychee is more of a Non-Action Big Bad, and Hatchiyack is a fighter, which better suits the franchise.
- Attack of the 50-Foot Whatever: Hatchiyack in one of the OVA's multiple paths.
- Back from the Dead: The ghost warriors at the final Destron Gas emitter.
- Big Bad: Dr. Lychee.
- Big Damn Heroes: Vegeta and Trunks decide to drop in on the party at the glacier and help destroy the Destron Gas emitter there.
- The Brute: Hatchiyack once he transforms from a supercomputer to a humanoid being.
- Emerald Power: Hatchiyack's energy glows an emerald green, kind of like a certain Legendary Super Saiyan...
- Excuse Plot: As expected from a video game story, the plot is very thin, even by Dragon Ball Z standards. This also applies to the appearances of Frieza, Cooler, Turles, and Slug. While it's understandable why Frieza and Cooler came back, the other ghost warriors that came back are clearly just there because they were popular at the time and are poorly mixed in.
- Expy: Hatchiyack is basically Broly if he had a science-oriented origin story... Before such a thing actually happened in Bio-Broly.
- He Who Fights Monsters: It's clear that Lychee let his obsession with getting revenge on the brutal Saiyans get the better of him and made him go too far.
- Mad Scientist: Dr. Lychee.
- Make My Monster Grow: Hatchiyack's super form.
- Misplaced Retribution: Lychee's plot to eradicate all Saiyans will also take out all of the humans, who were otherwise mere bystanders.
- Mook: Strange aliens who originally were just there to fulfill the random encounter quota.
- Multiple Endings:
- Hatchiyack was originally a Bonus Boss for defeating Lychee without using items. The OVA took the approach of making both scenarios possible depending on what actions are taken, but given that the remake only follows the Hatchiyack path, that's supposedly the canon one.
- The original OVA also had a lot of different approaches as to how Hatchiyack could be defeated, including the aforementioned giant Hatchiyack, but again, the remake makes the timing puzzle the canon ending.
- Nice Job Fixing It, Villain!: At one point, the heroes attempt to use Shenron to restore Bunbuck Island, which was destroyed by the Ghost Warriors, only to be interrupted by Pilaf stealing the Dragon Balls and using Shenron's first wish to paralyze the heroes so they can't interfere. His second wish is to restore his new palace and the island it was on... which happened to be Bunbuck Island.
- Ret-Canon: This was the first time it was stated that Saiyans didn't originate on the Planet Plant but invaded it after leaving their homeworlds. Dragon Ball GT and Dragon Ball Super made this canon.
- Save the World: The Z-Warriors have to save the world from a vengeful alien scientist.
- Send in the Clones: Hatchiyack in one of the multiple paths.
- The Bad Guy Wins: An ending in the Playdia version sees the heroes die in combat against the Ghost Warriors, resulting in Dr. Lychee successfully ruining the world with the Destron Gas.
- Too Dumb to Live: Kawazu had a plan that involves landmines... too bad he was up against Piccolo, who can simply levitate over them. Piccolo taunts him, asking if he can do the same. Kawazu attempts to do so... only to realize too late that he can't fly, and he falls... right on his own landmines. The resulting explosions not only kill Kawazu, but also destroys the Destron Gas generator as well. Piccolo even lampshades this by saying that he never thought that there was anyone more stupid than Mr. Satan.