What would Nintendo have to do to capture some of Sony and Microsoft's audience

[Soundwave]

To capture "some" is the operative word there right? "Some". This is assuming Nintendo is kinda cornered and the

- Cultivate good relationships with PC devs. Make a "New Nintendo Entertainment System" that plays Wii U games + PC games out of the box (so a Wii U + higher end 2015-era AMD GPU in one box for the Western market). Spec the GPU higher than either the X1 or PS4. Keep the Wii U around as a lower cost/more casual/kids friendly option. Support both with the same Nintendo games (1 SKU runs on both).

- Mark a slightly darker Zelda Wii U game. No cartoony graphics (sorry Aonuma).  

- Spin-off the Metroid games into a large sci-fi universe. Make a new bounty hunter and make a more action oriented game with said character.

- Buy up low cost exclusives on some legacy franchises that are dormant like Ridge Racer, Megaman, and Shenmue. Bring some Nintendo classics such as F-Zero as eShop/online titles.

- Reacquire the rights to the James Bond license from EON Productions. Make commercials featuring Daniel Craig and make new games around Bond for the Wii U/New NES/3DS.

- Keep funding/finacing more Bayonetta games even if Bayo 2 doesn't sell like crazy. Build that audience.

- Cut a deal with Square-Enix, joint project mega-RPG that features characters from all three companies (basically the Nintendo Hearts idea), in exchange for FF7-9 remakes on their hardware exclusive.

- Continue making FAMILY franchises! Nothing wrong with that, in fact they are an asset. But lets evolve past a 1950s Disney mentality here. The Harry Potter films are darker/grittier than most Nintendo franchises, lol, and Disney makes bank off Marvel Comics characters that truly appeal to people of *ALL* ages. Mimic that formula -- make family IP, but ones that still have enough appeal that they can resonate with adults as well as kids.