Nintendo's planning and development boss Shinya Takahashi announced Friday that the company is scrapping current development of Metroid Prime 4 and restarting production with the Metroid Prime series' original developer, Austin-based Nintendo subsidiary Retro Studios.

A new game in the Metroid Prime series has been long-awaited by fans, and Metroid Prime 4's development restart, and resulting delay, means that Nintendo will have a large Metroid Prime-shaped hole in its release schedule for years to come.

Takahashi said in a video announcement that the lack of real progress on the game has been "regrettable."

"The current development process has not reached the standards we seek in a sequel to the Metroid Prime series," Takahashi said. 

He said the current development status of the game is "very challenged," and said the shift in development studios was a "difficult decision."

Nintendo has never confirmed the studio that was initially working on Metroid Prime 4.

While Retro is taking the reins, Metroid Prime 4 producer Kensuke Tanabe will still be overseeing development. Takahashi made it clear that Retro will be restarting development on the game "from the beginning."

Metroid Prime 4 was originally teased at E3 in June 2017, with no other development update since. Takahashi did not give a window for a release date, only saying that "development time will be extensive."

Retro is responsible for three Metroid Prime games: Metroid Prime, Metroid Prime 2: Echoes, and Metroid Prime 3: Corruption, all of which were highly-rated, well-received 3D interpretations of the Metroid series.

Retro's latest game was Donkey Kong: Tropical Freeze for Nintendo Switch.