Nintendo has announced that it is "essentially... restarting development from the beginning" on the highly anticipated Metroid Prime 4, saying the game as it currently exists "has not reached the standards we seek in a sequel to the Metroid Prime series."

The surprise announcement comes from Nintendo General Manager for Development Shinya Takahashi. He said in a YouTube video posted this morning that current Metroid Prime 4 producer Kensuke Tanabe will begin "collaborating" on the game with Retro Studios, the studio responsible for the original Metroid Prime trilogy. Tanabe has previously worked as producer on multiple Retro-developed Metroid Prime titles.

"The current development status of the game is very challenged and we have made a very difficult decision as a development team," Takahashi said in the subtitled video. "We have decided to reexamine the development structure and change it."

"This change will essentially mean restarting development from the beginning, so the completion of the game will be delayed from our initial internal plan," Takahashi continued. "It will be a long road until the next time we will be able to update you on the development progress, and development time will be extensive."

The news is the first public update on the progress of Metroid Prime 4 since the game was announced with a brief logo reveal about 19 months ago . Nintendo made it clear at the time that Retro Studios would not be working on the project. Later reports suggested that Nintendo had tapped Namco Bandai for the game's development.

Major delays of big-name games aren't uncommon in the game industry: see the long saga of planned Grand Theft Auto V release dates or the four-year wait for Super Smash Bros. for Wii U for some examples.

What's notable here is how upfront Nintendo is being about the extent of the development troubles behind that delay. Admitting publicly that you're throwing out years of unsatisfactory work to start from scratch with a new developer is pretty rare in the secretive game industry. The move shows an uncharacteristic openness on Nintendo's part to alleviate fans' concerns about such a long wait for the game without any new public information.

Metroid Prime 4's delay leaves a big hole in the list of upcoming first-party Switch exclusives that have been publicly announced. An unnamed Pokemon RPG (which has also seen no public details announced) is the biggest name on that list, but new Luigi's Mansion, Animal Crossing, Fire Emblem, and Yoshi games are also planned for 2019.

As NPD recently reported, the Switch managed to have a very successful 2018 largely on the back of bestselling exclusives like Pokemon: Let's Go and Super Smash Bros. Ultimate. For 2019, it looks like it will be looking to do the same with one less major exclusive franchise on its release list.