The Nintendo Letter Box launches on the eShop this Thursday, 22nd December, Nintendo has announced.The free download lets you connect with your friends via StreetPass and SpotPass. You can send messages, 2D and 3D drawings, and photos and sound effects.Also out is Mighty Switch Force!, a platformer from Shantae: Risky's Revenge developer WayForward. You control a cybernetic police officer and shift the elements of the machine matrix of Planet Land back and forth. As you do. Pick it up for £5.40 / €6.00.It's joined in this week's update by the Game Boy version of Tetris, which launches on the Nintendo 3DS Virtual Console for £3.60 / €4.00.And on the Wii Shop Channel launches a demo of platform racer MotoHeroz, from Trials HD developer RedLynx.The rest: