The SNES Classic includes 21 classic SNES games, and almost half of them — 9 games — can be played by two players. Hence why the console includes two controllers.
But there is another game that actually supports two players, something Nintendo didn’t reveal.
The game is Yoshi’s Island, which requires a cheat code to unlock a 2-player mode.
In order to access the secret mode, go to the world map and press X X Y B A. This will reveal a secret menu that offers the 2-player mode with several mini games.
If you’ve manged to get an SNES Classic (it’s sold out right now), be sure to check out all of the cool game manuals that Nintendo made available online.