Edda - I can hear the overall emotionality, dynamics and mood intensifying.... Light choir, violin, piano - a standard but soulful set of instruments!
Expedition - WAAAH I LOVE THIS BELL AaaAH... (sorry). A calm, peaceful melody that creates a somewhat nostalgic feeling! I hear old life, sand, flutes, sand, wind, and... sand.
Lost Files - Oh! Looks like someone finally got to play the solo they've been wanting to play their whole life! The sounds of signals, light violins, bass strings, effects and BELLS make for an interesting experience! Did I encounter something difficult? Do I need C++ skills to understand what I found? Or will knowledge of morse code be enough?
Revelation - angelic choir... Light effects. Sand again? Bells? COOL!
All in all - you made a nice and atmospheric ambient, which I associate well with sand....
SAND