I have no idea why I didn't consider Donkey Kong. It may sound blasphemous but I've never actually played one of those games despite all the good things I've heard about them.
I was considering Chocobo Mystery Dungeon, but I honestly don't know much about it. Is it anything like Pokemon Mystery Dungeon? I've never played those games but I can stomach that sort of tile-based top-down combat more than the traditional JRPG combat.
Smash, I'm not especially great or into fighting games and I've heard that its singleplayer isn't exactly the best. It really seems made for multiplayer.
Treasure Tracker I hadn't considered either, seems like something that wouldn't do too poorly on the smaller screen undocked.
Not sure how I feel about the newer Yoshi games, are they like the Yoshi's Island I know of? Because I remember enjoying that.
steam has baba
I just saw a game called Ultrawings that could have scratched the flight sim itch I've been having recently, except it's apparently a port of a VR game from Steam which is unfortunate.
E: I just realized a lot of these games have demos so I can actually just try them first, derp. It's so weird having demos in this day and age...