A group of kids with special abilities (inventor, psychic, martial artist, etc.) team up to stop an alien invasion by collecting... melodies? Earthbound is one of Nintendo's strangest and most beloved games, taking place in a surreal version of America that - in cinematic terms - would probably play like a satirical throwback to 1980s classics like Goonies and E.T.
A young woman investigates the mysterious murder of her grandfather, only to dig up an ancient evil tome and sinister, eldritch Gods. It may be odd to think of a Nintendo movie that's rated "R" for nightmare imagery and violence, but Eternal Darkness: Sanity's Requiem might be a smart investment if Nintendo wants to be taken seriously as a production company.
It's The Fast and the Furious meets Star Wars in the sci-fi racing series F-Zero, which was always low on plot but high on octane. The game was about racing at impossible speeds through futuristic locales, but the movie would have to expand on that by building on the cast of characters and giving them an important reason to break the speed of sound in a hovercraft.
Fans have been clamoring for a Legend of Zelda movie for decades, and this is probably the biggest "no-brainer" if Nintendo wants to come rushing out of the gate with a blockbuster. The story of a boy named Link who teams up with a princess named Zelda to save the world from an evil sorcerer will need a lot of development if it's going to make an impact outside of the gaming community, but with the right filmmaker at the helm this could also be an instant classic.
A bounty hunter traveling the universe, hunting parasitic monsters. A Metroid movie would be pretty similar to a bunch of other films, so the trick would be focusing on the character of Samus and making her story feel distinctive from the Alien franchise, without denying audiences the same kind of inventive, smart, and sometimes disgusting thrills.
There are plenty of boxing movies in the world, but Punch-Out!! would have the freedom to be one of the craziest, with an underdog going up against a series of wild, unusual fighters who would make the villain of Rocky IV seem perfectly plausible.
The Star Fox games have always had a weird identity, torn between badass outer space action and cuddly-wuddly heroes (and villains). Any filmmaker tackling Star Fox would have a hard time striking the right balance, but if they succeed this could be a breakout smash for all-ages.