And yes, it's crossbuy for all.
Renegade Kid's exploration game will cross from 3DS to Wii U in North America on July 30.
Jools Watsham of Renegade Kid confirmed the date In his appearance on last night's edition of Nintendo World Rapport with Neal Ronaghan. Previously, Jools had confirmed the Wii U game would have crossbuy for the 3DS version, including for the prior buyers:
Xeodrifter Wii U has been approved for release by NOA! Hooray!! Release date coming soon. Cross-buy for one and all, new and old, etc. :)— Jools Watsham (@JoolsWatsham) July 10, 2015