Our game, Drive Across, recently launched on the Apple AppStore : https://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=1004305885&mt=8
It is a single level game with an intro.
We followed all best practices to minimize file sizes (Unity - Manual: Optimizing the size of the built iOS Player) and (Unity - Manual: Reducing the file size of your build).
When built using Mono scripting, the IPA was 20MB. Owing to new Apple submission rules, a Universal binary was required and we used IL2CPP scripting to generate a 35MB Universal binary.
Despite all best efforts, it is quite surprising & disappointing to find the app size on the store become almost double, to 60MB.
I am inclined to believe IL2CPP builds generate binaries that do not get optimized as easily by Apple after they DRM-protect files, and it would be very helpful to the developer community if Unity can add further information on file size optimization.