"New Contract: Perimeter Defense Book 3," by Michael Atamanov, 1st Person, Science Ficton/LitRPG

1st Person, Science Fiction/LitRPG. Produced by Tantor Media "The enemy's at the gate, the situation getting worse by the second, and Ruslan's employer hasn't done a good job (to put it mildly) of securing his successes. Now the star system Unatari is under threat from the Aliens. It's high time Ruslan came back in order to rescue everything he holds dear from imminent destruction and save Perimeter Defense - the game that has become his life." More info and reviews here.