As mentioned before, button A is a 'confirmation button' you'll use to enter the games, while you'll use button B to exit the games.

Every game will take approximately 30-60 seconds to load from the SD card.

Pressing the Select button will open the Game settings menu. You can mute the volume (press A to mute it automatically) or turn off the LEDs. To exit the
Settings, just press button B or the Select button.

If you want to know more about your games, you can press the Select button while you're in the menu. The pop-up message will show you who created the game you're about to play, who made music, as well as the description of the game. Once you're done reading it, press A, B, or the Select button.