You definitely nailed the post-apocalyptic style. The sense of vastness and desolation is awesome! As some other comments have mentioned, maybe you could vary the texture of the sound a bit more between pieces? For example, I could see parts where you could suddenly cut out the droning in the background, leaving one echoey instrument to play a melody, which could introduce a sense of loneliness and such to your tracks as well. Great job though, the atmospheric sound you created was spot on. Thanks for sharing!