You can transfer your account by creating a Link ID.

You can create a Link ID by clicking on the "三" icon on the upper right corner of the home screen, then selecting [Settings] → [Connect Account] →  [Link Data] →  [Create Link ID].
This ID can be used to transfer your data into another device.

*Keep in mind that linking your Sonic Rumble account with Twitch will not allow you to play your game data across different devices. Please use [Connect Account] in-game to do so.