Immersive! I have not played a solo TTRPG with such an immersive mechanic. The use of real time number station broadcasts and a one-time-pad actually sent a shiver up my spine. I almost felt as if I were doing something subversive...just like a real spy. If you are into spy stories along the lines of John LeCarre, not James Bond, you owe it to yourself to check out this game.