You can download Miitopia: Demo Version from Nintendo eShop by visiting the official gamepage*. To download from the gamepage, sign in then click “Free download”.
Please note: you can only appreciate the 3D effect of Nintendo 3DS, Nintendo 3DS XL, New Nintendo 3DS and New Nintendo 3DS XL on the system itself. Game visuals display in 2D on Nintendo 2DS and New Nintendo 2DS XL. All screenshots and game footage on this site are captured in 2D mode.
*Wireless broadband internet connection required. Internet usage charges may apply. Consult with your ISP. Registration of Nintendo Network ID and acceptance of the network related terms and privacy policies required.