"You're quite sharp!" :D
It took me 3 playthroughs to figure out who the ghost was, and I was pleasantly surprised when I got it right. All the way through 2Fort I thought I saw him on the walls, but the actual answer was staring me right in the face...
I really liked it, the music was perfect, great pictures (However in the Blu base I think you re-used one of the images from the Red Base). Although it was short, It was great and I think you should definately consider making a longer one.