I enjoyed this and liked the story it kept me guessing what was happening the whole way through! I really liked Cassian and Kellan, and the Shadow was the perfect Villian, though I must admit Vaida was my favourite. I'm a sucker for a sassy analyst! And after that ending/epilogue, I'll definitely be keeping my eye out for book 2! 
I also love how the author included a guide of characters, places, and the politics of the world as well as a pronunciation guide it was super useful to have to flick back to when needed!