Much like Scalzi's Old Man's War and its sequels, Terms of Enlistment and Lines of Departure are combat-grade military SF, and should come with an addiction warning. -io9 Frontlines is earnest, optimistic, and fun, even as it deals with subject matter that's intrinsically grim. It's a story that strikes the perfect balance between escapism and serious reflection, and it's the perfect military sci-fi series to escape into for a week or two. -The Verge