1) rain confirmed. i didnt know weather can change mid mission but apparently it can. at least rain and clouds that cast nice shadows on paris.
2) Rifles take the place of the melee weapon and are used as a blunt weapon. a very lethal one that can take out enemies in 1 or 2 hits sometimes.
3) In case of a blunt weapon like the rifle enemies who are down are not necessarily dead. they lie there incapacitated. you can finish them off with the HB.
4) It seems like enemies can follow you deep into buildings. not sure if this is realistic. we can see the player on the second floor of a building and when he kills attackers indoors once they die there is a "last known position" silhouette left where arno is standing. not sure if the way enemies know that arno is on that second floor because they've seen him come in or it's some magical senses.
5) enemies later in the game have 4 dots out of 5 above their heads. so it really seems like this is the rank of the enemy. However it doesnt seem like they fight more intelligently in any way than the rank 1 enemies.... however they do deal about 3 health chunks in one hit, so even the beefed up arno with 11 health chunks could have been killed in 4 hits. and health doesnt regen, but we knew that already.
6) the game seems to run smoothly on PS4 but there are the occasional NPCs or BG details pop-ins at medium distances. i only witnessed two occasions in the 20 minutes of gameplay so IMO its rare enough and i wouldnt mind. maybe i wasnt looking for it though... also there was this day time instance with a huge crowd and it doesnt seem like the frame rate dropped so much. still seemed smooth enough.
7) navigating through the crowd doesnt slow arno down very much.
8) nice little details i appreciated: when arno countered an enemy and punched him, the enemy stumbled backwards a little but since there was a carriage right behind him his stumbling changed direction realistically when he bumped against it. also when enemies were rushing towards arno indoors and there was a desk in the way they simply vaulted over it to get to him faster. i love those animations of the NPCs in the streets, arguing, pulling each other, talking, sword fighting....
9) small details i didnt like: some artificial changes in dropping direction happened to allow arno to free-run down - instead of dropping right downward his fall shifted him about 2 meters to the side towards a ledge. seems to be really rare. and enemy standing merely 8 meters away from his friend inside a room in the night didnt even notice arno slicing the other friend's throat, not was he bothered that right after arno stood in front of him reloading his rifle.
he later died.
10) heavy attacks trail glows red while normal attacks leave a white trail.
11) it seems like you can carry only about 5 or 6 of each consumables later on (we cant tell what memory sequence that was) so it doesnt seem like you can carry 15 medicines anymore