Hey a suggestion for OS X
When deploying an Application for OS X, Currently the app is generated inside a folder that contains not only the app, but all the resources. On the OS X environment, all of these resources should be placed inside the resources folder which can be found in the .app/contents/resources. As it stands i'm not sure if the games are submitted to the app store will pass because of this.
A work around i have in my head is:
1) use the package maker tool,
2) we configuring the package maker tool, set deploy location to "Applications" folder
3) create a shortcut to desktop
this goes against the entire framework of OS X. I know this is how windows operates, but OS X isn't windows.
I know wxWidgets uses a function called GetResourceDir and it works for both OS X and MSW. Some Pre processor definitions are used in wxWidgets to manipulate what you are attempting to do. Below is a link to the API Guide (note version 2.9 dev built is used, but this feature has been implemented since 2011)
http://docs.wxwidgets.org/trunk/classwx_standard_paths.html