Terraria not showing up in Store

[Nmoleo64]

I have a Nokia Lumia 520 with Windows 8.1, and I saw articles saying the game Terraria is out for Windows Phone, and it is not showing up in the store, but I went to my local Microsoft store, and it showed up on the Windows Phones there. What is wrong?

 

[switch side method]

Normally if the game is more powerful then the phone hardware then it wont show. For instance grand theft auto won't show on the 520 app store but its here for my 1520