This game has regional differences.
Dr. Chaos is a game about a guy saving his brother, the titular Dr. Chaos. Bet you didn't expect that!
Dr. Chaos was released in Japan for the Famicom Disk System peripheral, under the name Dr. Chaos: Jigoku no Tobira (The Door of Hell). Several gameplay mechanics, visuals, and audio were heavily modified for the US release.
Continuing the Game
In Japan, there is a file select feature which was removed from the US version. In the US version, there is a password feature replacing the file select feature.
The LIFE which shows your health and bottles below it in the Japanese version is kinda pointless because you can only save after dying and continuing the game starts you at 50HP without your life bottles filled. It should have been ITEM with the equipment and laser gun pieces and the life bottles you have below it.
The warp zones have been made longer and less compact in the US version.
First Person View
You are able to look behind you in the US version by moving your hand to the roof of the room.
Pausing and Resuming
Whenever you resume the game, the music starts over in the Japanese version. In the US version, when you resume, the music continues at where it was at.
While the game is paused in the US version, you can get a Password by pressing B or A.
In the US version, the Smorks appear in the Warp Zones, while in the Japanese version, they appear in the Mansion.
In the US version, some enemies were removed from some Warp Zones.
Michael's move speed was increased in the US version making it easier when jumping over holes and etc.
He also moves smoother in the Japanese version.
Rip the music.
The music was modified for the US release. The music tracks that didn't have Noise samples were added some.
- The FDS version uses all caps, whereas the NES version uses both upper-case and lower-case lettering.
- Furthermore, the text font has been changed.
- In the Japanese version, the Pony Canyon logo is over the middle of the mansion. In the NES version, it is placed on the lower-right corner of the screen.
- Takachan Iwamoto (Taku Iwamoto) was removed from the assistance role in the USA release, as well as Ruchan Takayasu.
- PRESENTED BY PONY INCORPORATION was changed to Presented by Pony Canyon inc.
- The © 1987 PONY INC. copyright was changed to ©1988 FCI/PONY CANYON in the USA release.