Grant Kirkhope, music composer for Rare at the time, reused songs he had composed for Rare's unreleased game Project: Dream for several other titles, including Banjo-Kazooie, Banjo-Tooie, Donkey Kong 64 and Viva Piñata.
According to Chris Seavor (creator of Conker's Bad Fur Day), Rare wanted to explore 'amiibo styled things' way back during the days of the Nintendo 64. Rare even made figures of two of their characters for an unproduced fantasy video game called Urchin. The idea went nowhere with Rare and Nintendo at the time. Later, Nintendo decided to introduce the concept of Amiibos for the Nintendo Wii U and 3DS on June 10, 2014.
According to former Rareware employee Chris Seavor, when the company was purchased by Microsoft, a number of the Microsoft executives thought that they had the rights to Donkey Kong until Rare corrected them.
One of the prototype games Rare had created to test programming for the Kinect had the player control a seagull, and attempt to poo on passers by.
When Microsoft had acquired Rare, they'd decided to keep their in-house Game Boy team as Microsoft had no intentions of entering the handheld market. Rare would continue to develop games for the Game Boy Advance and Nintendo DS. Microsoft themselves had also released other games on rival platforrms.