I currently have a world that I've been playing on the 1.8 snapshots on my PC (currently 14W30C), and I wanted to play this world on my laptop, so I copied the 'World' directory from the
%appdata%\.minecraft\saves directory to my laptop.
The world copied over just fine and everything was as expected with the exception of one thing. All of my achievements were lost. I thought achievements were supposed to be per world since 1.7 and as such assumed they'd be stored within the world save folder, but it seems like this isn't the case.
What do I need to do to transport the achievements between different computers with the world save?
Supporting Info: I have the same snapshot on both systems, using the same Minecraft logon, both computers running Windows 8.1 x64