Well, I must admit I'm pretty impressed with my first evening of play.
The open world is very large, I decided to go on a tour along the outer edges of the map in a circle, and it took me hours... and that's just going around the edge of the map, barely scratching the surface of everything that lies within. The attention to detail is awesome, there's heaps of diversity and plenty of things around that spark your interest.
The game itself is running super smooth for me, so it makes me wonder why people with much beefier pc's then I have complain about the game running crappy on even low settings, I wonder if they have their drivers updated... I'm running on high, and it's smooth all the way, the game engine seems to work great for me, and the lighting, weather effects etc are impressive. Rainy nights are very atmospheric and simply look awesome. As with scenery, little details keep impressing me, like a small coke can being blown around the floor by the wind, and the destructibility of the environment, either by explosions, shooting or running into it with a vehicle.
The driving at first I thought was crap, but after getting used to it some, I'm now handbreakturning my way through the city with relative ease, and that's driving with keyboard. I do understand the initial criticism about it, but seriously, all it takes is some getting used to, and having the sense not to want to take 90 degree corners at full speed and you're good to go.
Gameplaywise I still have some doubts. The hacking is fun, and not always as easy as pushing a single button. Though sometimes a single button push is enough, you still need to time it right, and more often you'll have to jump from cam to cam to fusebox to whatever to get things done the way you want it. There aremore elaborate hacking puzzles too.
There's plenty of secrets and objects and stuff to be found, not unsimilar of assassins creed and far cry, and although not really needed, if you're a completionist there's lots of stuff to be looked for and keep you busy for a 100 hours.
The main quest line if you want to call it that, I barely played it, and judging from the stories online you could rush through it in about 20 hours, and according to most reviews the story is a bit thin. To be honest I can see myself end up agreeing with that in the end, but I'm way to much a fan of open world games to judge this game on that fact alone.
I must admit the gameplay is very ubisoft like in the sense of farcry and asscreed, you can scale buildings just like towers in those other games to unlock map info, and lots of the side activities boil down to the fighting and treasure hunting of the aforementioned games.However it is fun to do combined with your hacking skills, and there's several way's to finish a (side-) mission, stealthy, hacking or guns blazing, on foot, by car, bike boat or el-train.
If you rush through this game I can see it being a slight disappointment to some people, however, if you have the ability to enjoy yourself in an open world game even with no mission active, you can have heaps of fun for a very long time in this game.
Unfortunately U-play is having its issues, so I haven't been able to check out the multiplayer elements of this game. I've seen a bunch on streams though, and when U-play works it is actually fun to see how MP is half intergrated in SP withpeople being able to hack their way into your singleplayer experience in several way, next to more conventional MP modes (like freeroam mode and racing for example). You can even influence other peoples game by tablet apps, so the game is quite modern in that sense.
However, MP is suffering from connectivity issues at the moment, which is a shame.
All in all the sandbox is there with lot's of toys in it, there's plenty to play with and I'm not disappointed at all so far. It's up to what you do with it though, and if open world is not your thing, or if you can only enjoy open world when you've got a beefy story taking you by the hand this might not be your game. I'm impressed though, not really by the story, only partly by the gameplay, but mostly by the world it's in.
Concluding, it is a typical Ubisoft 'a little bit of everything'game, with lots of elements, but non are really in depth; There's driving, but it's arcady, there's shooting, but not heaps of guns and upgrades, there's hacking, but not on the level of intricate puzzling, there's a storyline, but not indepth enough to make you cry, there's secrets and loot, but nothing extremely rewarding, there's a skill tree, but it doesn't have extensive branches.
What is impressiveis the world itself, and how the game engine makes it look, I must admit to that. How much you'll enjoy yourself is really depending on what you're looking for in a game, but you certainly can enjoy yourself with this game, in the same way as playing with lego bricks can be enjoying, it's just what you make of it.