Directly to you from Twitter:
Tempest Trials: Resonating Fangs has begun! This time, enemies won't revive. The base score in Normal & Hard has in… twitter.com/i/web/status/8…—
Nintendo of America (@NintendoAmerica) July 07, 2017
…Wanna play? Buy a 3DS.
That being said, click on Fire Emblem Heroes for everything you need to know about the game. 😀