...Well, primarily because we didn't receive code until today. It seems some multi-format sites have had console versions ahead of release, but no dice in PC-land, at least not here. Though folk in the US have been able to buy the game since 12am. Maybe I should have moved to America and pulled an all-nighter just for this.
Whether this is related to various reports today that Ubisoft jumpy-stabby sequel has a number of performance issues, particularly with regard to framefrate drops and pop-in, we can't know. Just wanted to tell you why we won't be holding forth one way or another for a few days yet, basically.
Edit: game is now running. Technical thoughts tomorrow morning, technically.
We're also not in a position to let you know first-hand whether the PC version suffers from said issues, as it crashes on startup on our reviewer's system. We're trying to get this resolved (currently all 42GB is downloading for a second time), and hope to have some preliminary word-thinks for you tomorrow.
We'll also note at this point that Assassin's Creed Unity's review embargo was set for 12 hours after the game had launched in the US. Expect to see some reviews crop up soon after 5pm UK time today, but ours won't be among them. Waaah it's not fair etc, etc, etc videogames.