Packaging a node-webkit app (exe) to Win 8.1 appx - windows-8.1

Question

I am attempting to transform a built node-webkit app that I created into an executable appx Win 8.1 Metro App.
After creating my appx package and signing it, and creating my AppxManifest.xml file :
<?xml version="1.0" encoding="utf-8"?>
<Package xmlns="http://schemas.microsoft.com/appx/2010/manifest">
<Identity Name="bouveret" Version="1.0.0.0" Publisher="CN=Mc" />
<Properties>
<DisplayName>iMotion</DisplayName>
<PublisherDisplayName>XXX</PublisherDisplayName>
<Logo>logo.png</Logo>
</Properties>
<Prerequisites>
<OSMinVersion>6.2.1</OSMinVersion>
<OSMaxVersionTested>6.2.1</OSMaxVersionTested>
</Prerequisites>
<Resources>
<Resource Language="fr" />
</Resources>
<Applications>
<Application Id="bouveret" Executable="bouveret.exe" EntryPoint="WinMain">
<VisualElements DisplayName="iMotion" Logo="logo.png" SmallLogo="logo.png" Description="iMotion" ForegroundText="light" BackgroundColor="#000000" ToastCapable="false">
<DefaultTile ShowName="allLogos" ShortName="iMotion" WideLogo="logo.png" />
<SplashScreen Image="logo.png" />
<InitialRotationPreference>
<Rotation Preference="portrait" />
</InitialRotationPreference>
</VisualElements>
</Application>
</Applications>
</Package>
I manage to install it via Powershell, but I suspect it doesn't manage to run the entry point for the app. NW apps don't have a C# interface I can use to set a proper entry point.
Anyone has any idea on which entry point should be set? The executable launches itself properly, but the appx package doesn't launch anything : I see the logo on a black background and then it minimizes itself to the desktop without any debug trace.
Thank you.