AKA: Atlantis no Nazo

Mystery of Atlantis is a Famicom game by Sunsoft

Activision worked on an English version, turning it into a sequel to the unremarkable Super Pitfall. It was never released, but a ROM is available online. There are some differences, including the removal of powerups.

You can read more about the English version at Dream and Friends, which also has the ROM for download.

• Atlantis no Nazo
• Disgruntled Designer - Atsushi Sakai (programmer) interview, in Japanese.