Likewise, Gunbuster's first launch is adapted from the pivotal battle of Getter Robo G, where the machine rises out the ocean, arms folded, and decimates the enemy's forces.
The final scene also homages Musashi ripping the reactor from his machine's chest at the end of Getter Robo.
Gunbuster is also shown launching missiles/lasers from all over its body in an identical fashion to Ideon.
Although never used in the show, an official card game showed Gunbuster using the Choudenji Yo-Yo and Choudenji Spin from Combattler V.
Hideaki Anno gave Gunbuster a single eye because he thought it was unique. However, he later decided it was a mistake because it didn't keep the robot recognizable when in shadows. This is why EVA-01 was drawn with two glowing, white eyes on a gloomy purple body.