From the Super Mario Wiki
Retro Studios is an American video game company based in Austin, Texas. They are a subsidiary of Nintendo founded in 1998. They are best known for the development of the Metroid Prime series. At E3 2010, it was revealed that they were reviving the Donkey Kong Country series by helping Nintendo create Donkey Kong Country Returns, which was first released on November 21, 2010, in America. They helped develop Mario Kart 7 for the Nintendo 3DS along with Nintendo EAD by contributing assets for the Donkey Kong tracks within the game. While Donkey Kong Country Returns 3D was developed by Monster Games, Retro Studios help with the collaboration for the remake. Retro Studios also developed Donkey Kong Country: Tropical Freeze.
Mario games developed by Retro Studios