Cool! The story definately scratches the mystery-itch well. Having a gripping story can be a giant hook for keeping people engaged. The fact the story is told this rather subtle way through e-mails is a funky trick, keeping the narration work low while forcing the imagination of people. And the way you build up mystery is great.
The mini-games do a great job at “distracting” from the story part - I even thought the auto-buttons weren’t really needed. In a way the monotony of the tasks kinda elevated every story fragment - That way it reminded me to “Papers Please”. In contrast to that game having established the connection and scanned the signal at least feels like an accomplishment, so it is more motivating.
Are you entertaining the idea of developing this into a full-fledged game? With some basic graphics this could turn into a hit. Maybe i’ll throw something together over the next weekend… I don’t have much time, but i like a challenge. :D