So, I've played maybe 1.5 hours beyond the fairly atrocious opening (except for Vaas; he's awesome, but fuck me, do I hate MIA) and my most prevalent emotion towards the game is just how much I dislike the colour palette. The greens are too green, the blues too blue and the yellows - you guessed it - too yellow.
It's as if they've gone so far out of their way to shit on the oft maligned 'brown/grey video game palette' stigma, that they've completely overcooked it and ventured into ugly territory. Thus far, the surroundings look like an actual user-created sandbox; a giant area birthed inside a stock level-editing tool. It is completely devoid of any sort of atmosphere that was present in Far Cry 2.
The HUD is also a bit of a mess, as has probably been covered numerous times, i.e. the enormous check-sheet that tracks how many plants you need collect for the mission that just does not disappear. Idiotic.
As far as gameplay goes, everything is in order. Guns feel nice to shoot for the most part and movement is well done, if not seemingly marred by a bit of jank that I can't quite put my finger on. As someone mentioned earlier, the game lends itself to a somewhat floaty and agile movement model that was nailed in Dishonored, but isn't as deftly executed here.
I really dig the weapon modelling, as well as their presence in the world, i.e. aiming around cover and being pulled in against walls and whatnot. That stuff is great.
So, yeah. These are 100% first impressions, so don't rip me apart. I'm sure that the game opens up a lot more and becomes a lot more enjoyable, but I'm just not feeling the urge to go on. We shall see!