In Warlock Zone IV, a villager will reference the Konami Code by telling the player:
"Just between you and me... if you use the command "Up Up Down Down L R L R B A", nothing will happen."
The Japanese version of the game had some content that was cut when it was released overseas. In Warlock Zone III, there was a show consisting of Ebisumaru (Dr. Yang) dancing around and farting at the end. And in Warlock Zone VI, there was a Geisha Strip Club with an accessible strip show, although there is no explicit nudity.
In the Game Center, for $100 players can play a modified version of the first level of Gradius.
Konami Girl, the sidekick of Konami Man from the Konami Wai Wai World games for the Famicom, appears as the host of the Game Center.
In the western release, the main characters Goemon and Ebisumaru are named Kid Ying and Dr. Yang respectively, a possible reference to the Yin-Yang, a symbol which represents seemingly opposite or contrary forces. English translations of later installments retain the character's original names.
The maze, concentration and trivia huts feature a picture of a man wearing a red winged hat with a K on it. This is Konami Man, Konami's then mascot and protagonist of the Konami Wai Wai World games for the Famicom, released exclusively in Japan.