The story in this version is more detailed than in the original release. Professor Imes was a famous archaeologist particularly interested in the old Mayan civilization. Having heard of a powerful artifact known as the Sun Key, which is apparently able to unlock the secrets of the Maya, professor assembled a team and traveled to the ruins of Chichen Itza. However, he and his team have mysterious disappeared; only his guide Jose was able to escape, delivering the news to the professor's daughter.
Unlike in the original release, the player character travels to the Yucatan with the daughter of Professor Imes and the guide Jose. Both have special abilities which are sometimes needed to solve puzzles: the young woman is musically talented, and Jose is able to move heavy objects. Due to these changes, some of the locations and puzzles have been altered in this version.
Another significant gameplay change is the introduction of role-playing elements. Solving puzzles and defeating demons in turn-based combat grants the protagonist experience points. Even though combat is very sparse in the game, taking on stronger foes can be futile if the player hasn't gathered enough experience by completing other tasks beforehand.
This game features a room where if the player becomes trapped it actually tells them to RESET the console and start over. Although it wasn't uncommon for an NES game to make you restart after a game over, this is one of the few games that made the player start over themselves when they got stuck.