UPDATE: It seems as though there may be framerate issues across all platforms, with NowGamer reporting Xbox One issues as well:

'I would like to warn anyone thinking about buying this game,' said thewouldbeking. 'I got it with my Xbox bundle. I just started it, and it runs sub 30 frames per second constantly. I would advise to wait until its fixed or not buy it at all. It is practically unplayable.'

This is not an Assassin's Creed: Unity review. I'm technically not permitted to make any value judgements on the game until 5PM GMT this evening, and I've not finished it so I couldn't even if I were able. But the game is now out in the US, and something needs to be said about the state that the game is in.

Even after playing for just under ten hours, (UPDATE: To be clear, this original report was written after installing the ~900MB patch) it's clear that there are some glaring technical issues with Assassin's Creed: Unity.

In terms of technical execution, the game is an utter shambles on PS4 -- I can't speak first-hand regarding other versions. Glitches abound, responsiveness is laughable, the context-sensitive detection areas around interactive objects like key mission items and reward chests are patchy and inconsistent. The crowds are impressive, the game does a fine job of creating a visually engaging representation of Paris, but the framerate is horrible. Lengthy jumps see Arno hang in the air, crippling slowdown is everywhere (especially if you get into cover), and although the free-running repertoire and animation sets have been massively expanded, its not uncommon to see the framerate juddering down below the 15 fps mark.

At one point, I thought the whole game was going to crash, Arno pirouetting about in clunky slow-motion that certainly hadn't been triggered deliberately.

Pop-in is also a problem, especially when it comes to transitioning between indoor environments and the outdoors. Rooms will occasionally only reveal a back wall as you're climbing in the through the window, and its not uncommon for a building only a street or two away to seemingly materialise out of thin air.