Dr. Jekyll is on his way to his wedding with the lovely Miss Millicent. As he walks to the church with his cane in hand, several townspeople, animals, and other obstacles accost him, causing him to become angry. If his anger reaches a certain level, he transforms into Mr. Hyde and is taken to a nightmarish world of monsters. As Mr. Hyde kills these monsters, his anger abates and eventually he transforms back into Dr. Jekyll.
There are two endings to the game. The normal ending occurs when Dr. Jekyll reaches the church at the end of the sixth level. Dr. Jekyll weds Miss Millicent and 'END' is displayed with the wedding march playing in the background. The alternative ending occurs when Mr. Hyde reaches the church. In this case, a boss named Letule appears. After defeating the boss, Mr. Hyde transforms back into Dr. Jekyll. A more detailed scene of the wedding is shown with Dr. Jekyll kissing Miss Millicent. The screen fades with 'END' displayed, and lightning strikes a few moments later. A silhouette of what appears to be Mr. Hyde with a cross inserted into his back appears.
