If only MS didn't own it. Loved the game on N64 but aged badly. Still a fantastic OST. 

Yeah, a new Donkey Kong Country to complete the Returns Trilogy.

From a sales perspective, it would make more sense for Retro to be moved back to making a DK platforming game, it would also allow Nintendo to continue to use the momentum of Bananza's success to drive continued popularity of the DK IP the coming years. Metroid Prime is not viable in its current form, a 3D Metroid game will likely need to become a third person adventure game to be more relevant in the future.

As long as it's not the tired "Third person but the character is constantly over to the left or right of the screen." game. That doesn't feel third person. -_-

Reuse some assets for Metroid Prime 4 to make 5. Then reuse some assets from Tropical Freeze to make a sequel that wraps up Retro's trilogy of DK games.

Given that Prime 4 is a Switch 1 game and Tropical Freeze a Wii U game, I'd rather they not reuse assets but make much better looking ones. 

Unless you meant non-graphical assets like code for things like collision, controls, etc.

Non-graphical if they can.

Asset-reusing sequels are indeed best on the same platform. Games like Majora's Mask and Super Mario Galaxy 2 are beloved. 

And I don't want to underestimate the craft in making a 2D platformer, but it strikes me as something that can be done in 2-4 years, not 5 or longer like some games. 

Works for me. That's basically how Majora's Mask was made.

2D Donkey Kong - one to finish off and make the DK Returns "Trilogy" feel like a trilogy.