Metroid would be easy to make a movie of
Just have half the movie a close up of samus' face as she monologues
I feel a good Metroid movie would mostly consist of flashbacks to Samus's past while she goes through the first game.
Continuing on...
F-Zero doesn't have much of a story so there's room to work with but it would be nice if Captain Falcon was the main character and not playing mentor to generic anime hero #4614
Earthbound and Mother 3... I don't think they'd work as movies. Maybe a Netflix series.
Fire Emblem seems like a good one to do but then you got the "Spirits Within" problem that you'll lose interest if you make an original story instead of adapting one of the bigger games.
Ice Climbers... In my opinion the world needs a cutesy movie about ice climbing instead of everyone slowly dying from the cool and trying to murder each other.
Game & Watch... Let's see how the emoji movie turns out first.
Wario seems more like Saturday Morning Cartoon material or a villain in a Mario movie
Kid Icarus, especially now it got some personality could work.
Pikmin already had a couple of short movies. How's they turn out? I haven't watched them yet.
ROB... I got nothing.
Animal Crossing already had a movie. Don't think it ever got dubbed.
Wii Fit... I got less than what I got for ROB.
Punch Out would need to try and be different from Rocky but I think it could work.
Xenoblade has the opposite problem to most in that it has too much story. I have no idea how to cram-a-lam that into 90 minutes.
Duck Hunt...
Splatoon has an interesting world but it'd take a lot to make an intense movie about a paintball war.