Select “Universal 8.1” SDK under Windows Store platform.
No worries. Here’s all of them:
| UNITY_WP8 | defined on Windows Phone 8.0 apps only; |
| UNITY_WP_8_1 | defined on Windows Phone 8.1 and Universal 8.1 apps when running on Windows phone device; |
| UNITY_METRO | defined on Windows Phone 8.1, Windows Store 8.0, Windows Store 8.1 and Universal 8.1 apps; |
| UNITY_METRO_8_0 | defined on Windows Store 8.0 apps; |
| UNITY_METRO_8_1 | defined on Windows Store 8.1 and Universal 8.1 apps when running on Windows device; |
| UNITY_WINRT | defined on both Windows Phone and Windows Store apps, regardless of version; |
| UNITY_WINRT_8_0 | defined on Windows Phone 8.0 and Windows Store 8.0 apps; |
| UNITY_WINRT_8_1 | defined on Windows Phone 8.1, Windows Store 8.1 and Universal apps regardless of device it’s running on; |
| NETFX_CORE | defined on Windows Store 8.0, Windows Store 8.1, Windows Phone 8.1 and Universal 8.1 scripts that are compiled using Microsoft C# compiler. |
Plugins for Windows Phone 8.1 and Windows Store apps should be put to Assets\Plugins\Metro directory or one of its subdirectories:
Assets\Plugins\Metro - plugins in this directory will be used in Windows Phone 8.1 and Windows Store 8.0/8.1 apps; Assets\Plugins\Metro\Win80 - plugins in this directory will be used in Windows Store 8.0 apps; Assets\Plugins\Metro\Win81 - plugins in this directory will be used in Windows Store 8.1 apps; Assets\Plugins\Metro\WindowsPhone81 - plugins in this directory will be used in Windows Phone 8.1 apps.
Note: We do not support Windows Phone 8.1 silverlight assemblies as plugins for Windows Phone 8.1.