Bottom Line Up Front: This is a Beta. Still quite a bit of work to go. Under normal circumstances I'd probably only give this a 2 star rating. However, The setting is fun and despite being a mash up of a lot of different stories from different media it hangs together surprisingly well.
Needs a Beastiary or equivalent. The varying antagonists are spread out throughout the book and therefore difficult to find quickly. The Archetypes are pretty limited considering the vastness of the Dominion. The Archetypes use the standard 3 refresh 3 stunts and +4 pinnacle skill pyramid. You don't use a standard phase trio but this is adequately explained and appropriate for the setting. However, these rather pedestrian beginners are supposed to represent the God-like Deipotents and their Exalted-Human minions. Regular old Humans don't even get a mention.
The book would benefit from changing the chapter on themes into something more closely resembling the "Game Creation" chapter from FATE Core. The history is given in some detail but there are no pre-made campaigns. The author shows some possible themes, but doesn't elaborate on how to turn those themes into a campaign unique to the setting. If he doesn't do that then this book needs some pre-made campaigns or some varying story seeds. Why? The history and the setting is huge. Having a way to create a starting point or barring that having some actual starting points would be helpful.
Initiative is handled quite differently in Baroque. You roll your Tactics skill and whoever scores higher goes first. Then they get to choose who goes next. If someone wants to interrupt they can use a Fate Point to go next.
The Notice skill has been removed. In its place an new action has been created; Notice. Each skill has a Notice element. Use Tactics to Notice and Ambush. Use Technosophy to Notice a malfunctioning system. Etc. In most situations Notice can be used at the same time other actions are used so you don't lose your normal actions in a round.
I sometimes feel as I read the book that new rules were added for the sake of adding new rules without gaining any real benefit or without highlighting the really unique setting. I also feel as if there wasn't a great deal of time spent playtesting.
There are other niggling things that the author will probably fix in the near future. No character sheet. Paucity of Art (it is evocative what there is of it). No back cover.
[3 of 5 Stars!]