According to the Paul Gale Network, Retro Studios is working on a project for Wii U with the rumoured title Star Fox - Metroid: Fusion Saga.
It is rumoured that Retro Studios had two games it wanted to develop - a third-person sci-fi action game and an entry in the Star Fox series. Rather than make two games, Nintendo is believed to have combined them into one title that would also draw from the studio's experience working on the Metroid Prime trilogy.
The game would play half as Samus exploring on a planet's surface and half as Fox McCloud in space combat missions. Later in the game there would be opportunities to switch roles, with Samus able to fly her space ship in combat missions and Fox able to fight on the planet's surface from a third-person perspective.
If confirmed, it would not be the first time Nintendo has meshed two games together for development on a new system.
The early Gamecube title Star Fox Adventures was planned by developer Rare as a new franchise called 'Dinosaur Planet'. The Star Fox characters and space missions were a relatively late addition, to combine the new game with Nintendo's existing series.
The initial report states multiple times that the game is currently only a rumour. The Paul Gale Network's source claims that a crossover game was at least a concept in the planning stages between Nintendo and Retro Studios.
It is believed to be the same Wii U game Retro Studios referred to last year as "a project everyone wants us to do".
Retro Studios is best known for its work on the Metroid Prime trilogy on Gamecube and Wii, as well as 2010's Donkey Kong Country Returns.
It has also been speculated that Star Fox - Metroid: Fusion Saga will be officially announced during E3 2012 next month.