The Anubis War is a Military Science Fiction novel (MilSF) novel self-published by author David R. Packer and it's also an entrant in this year's Self-Published Science Fiction Competition (SPSFC4), of which I am a Judge. The novel is short and also the first in a series, although it has a complete arc kinda, and features a soldier Vasco coming out of retirement to join a mission on behalf of the Polity to conquer a distant human colony and bring it back under the empire's control. So you have some pretty classic themes here of Anti-Imperialism and Anti-Colonialism underlining a book which to some extent features a ginormous overwhelming military force facing off against guerillas with more skill than the Empire expects.
Unfortunately, while the core themes and ideas of The Anubis War may be good, the book is derailed by a number of poor choices. First, the book is kind of obsessed with the military tech that is used by both sides and spends pages upon pages going through it and how warfare is conducted and nearly all of it does not actually matter...and this slows the pacing and makes the book a slog at times. Second, the main character isn't very interesting and none of the other characters are really ever developed beyond simple archetypes (backstabbing Intelligence Agent Friend, Greedy Warlord Commander, Mysterious Supersoldier who says cryptic comments from a long lost land, etc.). Third, the plot requires kind of a level of belief in the stupidity and intelligence of various forces to the extent that honestly broke credibility. And all of the above is done without any subtlety to a ridiculous extent. I'm not the biggest fan of MilSF, but I doubt even the biggest MilSF fan will find the Anubis War among their favorites.