Mechanicus is both a great Xcom style game in it's own right and also a really good look at the weirdness of the Adeptus Mechanicus, it's also written by a regular Black Library authors (GW's publishing arm).
I can believe it, while the story isn't much to write home about, its discussion on the divisions within the AdMech, how they approach xenotech and their parallels with the Necrons is more than I've come to expect from a lot of Warhammer games.