Dr. Jekyll and Mr. Hyde

Dr. Jekyll and Mr. Hyde is based off the 17th-Century play of the same name. It's as good as it sounds.

Stage Skip
At the title screen, when the title menu cursor points to the "START" option, press B on Controller 2, then press Up, B, Right, Left, Down, Right, Left, A, B, Right, Select, B, Down, Start on Controller 1. During gameplay, on Controller 2, press A to skip the current level (up to the ending sequence) or B to switch between the Jekyll and Hyde modes.

Stage Order
Two stages in the US release were removed.
 * Level 1 (the city) in Japan
 * Level 3 (the alley) in Japan

Level Order
For whatever reason, two levels were repeated to compensate for the removed levels. In addition, the level orders were rearranged and a chart below illustrates this:

Bomb Detonation Time
In the Japanese version, the bombs vary in fuse time by level. In the US version, by every stage the time it takes for the bombs to detonate get shorter and shorter.