Game #64 is just a blinking cursor. No instructions. You type: I'm sorry. The cursor blinks three times, then erases it. You type: I forgive you. The game saves. You can never play #64 again.
If you are using an , a Miyoo Mini , or an RG35XX , performance matters.
If you are a purist who wants to play The Legend of Zelda with a save file and a battery backup, just download the standalone ROM. Multicarts historically struggle with save states or battery saves.