According to an article in the fourth volume of the Computer Entertainer magazine, publisher Broderbund explained that the reason the hero and Princess Mariko are blonde in spite of the game taking place in Japan is because of Japanese preferences at the time, as heroes in adventure manga often had blonde hair.
During the start of the game, walking backwards towards the cliff while in the fighting stance will cause the player to fall down to their death, getting an instant game over.
The Atari 7200 port contains text hidden in the game's coding, which reads "MOMMY AND ME ARE ONE." This text is a paraphrasing of a 1985 experiment on the effects of subliminal messages on the unconscious mind, where the phrase "Mommy and I are one" was allegedly effective at raising self-motivation.
At the end of the game, the player is meant to approach the princess in the stand-by/running mode to end the game properly. If the player enters a fighting stance and then approaches the princess, she will kick them, thinking you are an enemy, which will kill them in one hit.
Playing the B-side of the disc would make the game play upside down.