I'd suggest changing the scoring method. The odds are MUCH higher of getting a guess wrong as opposed to right, so fewer guesses seem better in this, and it kind of ruins the fun of trying to guess anything too far from obvious. I'd suggest just giving people points for being right, and limiting the number of guesses to prevent people from throwing everything against the wall to see what sticks.
But that's just my opinion. I'll just throw up my guesses cause why not.
1. N64 games for Nintendo Online- They're adding such obscure games that they need something for this service.
2. Wii Sports Adventure- Similar to ring fit by focused on Sports titles.
3. Nintenpets- I figure they will try to revive one of their big DS/Wii era titles, so that's kind of an alternate guess.
4. Crash for Smash- Honestly would not be thrilled about this, but hard to think of another name.
5. Great Ace Attorney localization- Seems clear this is happening, the only question is whether or not it would be announced for a direct. Since this has been a Nintendo-centric franchise, it'd make sense.
6. Skyward Sword Remake- Something has to be done for Zelda. BOTW 2 would not come out in the first half of the year. It seems more likely that a remake would come out before July. They've remade pretty much every 3D game, so this makes the most sense, especially since Skyward Sword used motion plus which the Switch can replicate pretty effectively.
7. Mario and Rabbids 2- Ubisoft has been doing some things that would indicate this is coming. And, it's hard to see why not. Game was a big success, and there's no reason for them not to cash in. This seems big enough to be the first half of the year's "big" title, but not big enough that it'd be a holiday release.
8. Metroid Prime 4- I think they'll show one thing that's coming out in the future as their "one more thing". Either BOTW 2, Bayonetta 3, or Prime 4. Just going to guess Prime 4.