In addition, sales of other titles and titles released by other software publishers continued to grow steadily, bringing the total number of million-seller titles during this period to 20, including the titles of other software publishers
Those 20 games sold 1m+ between April and December 2018.
From Nintendo :
Super Smash Bros, Pokemon, Super Mario Party, Mario Kart, Odyssey, BotW, Splatoon 2, Mario Tennis Aces, Kirby, Donkey Kong, Labo Kit 1, Captain Toad.
From 3rd party :
Octopath (confirmed), Minecraft,...
+ Crash Bandicoot, Mario + Rabbids, Diablo ?, FIFA ?
I thought that it was an interesting thing to point out, 3rd party games also thrives on Switch despite the output being softer than on other platforms. Sucks that we don't have the names of the 3rd-party games.