Quite an exciting story. A bit of a stretch at times, but what suspense story isn't?
I understand the work has undergone a new edit since I got my copy, so I won't comment on the challenges I encountered.
I had my usual issues with first person - not much to do with the story, more my personal preference, although to me this highlighted one of the reasons I'm not a fan: I found the two character's "voices" to be very similar. If I stopped in the middle of a chapter for any reason, when I came back, it was hard to tell whose POV I was in until an external clue was given.
Other than that, it was exciting and quite well constructed - although I was a bit confused as to what, exactly, the villain's goals really were.