Witcher 3 format/vibes with a lot of conversations, choices on how you do things (combat, stealth, persusasion, hacking, intimidation).
Alternative timeline: this future developed from the 1980s, not our own timeline, and Cyberpunk 2020 and the all the existing lore remains intact. Characters from the existing Cyberpunk products will appear, but they're a bit coy about how (as the video game is set 57 years after the P&P RPG).
You can take people down through stealth attacks.
Full day/night cycle and variable weather conditions.
Six distinct regions of the city. Very rich high-end areas and a massive, near-lawless region called Pacifica.
The game will let you enter lots of buildings.
Along with normal areas, the game has several "megatowers", which are basically Judge Dredd blocs complete with their own ecosystems, factions and shops.
Massive verticality to the game.
EXP is divided into two strands: normal EXP is accrued from completing the main quests. Street EXP or street cred is mostly gained from side-missions. As it increases, your rep on the street goes up and you start opening up new vendors. I imagine this all impacts on quests, how likely you are to get attacked etc.
CDPR emphasise that this is a roleplaying game with shooter elements, not an action game. Choice and narrative consequence is the game's #1 emphasis.
Your character is called "Vee" but you can define their gender, backstory and abilities. There are both male and female voice options for the character.
There are perks, skills and cyberware in the game that define your abilities. There are template classes you can use for guidance, but not hard-set classes.
The main story is noir-influenced with an emphasis on the inequality between the streets and the rich people living in the towers above.
Smart weapons which missiles and bullets.
Drivable cars and motorcycles, and some other vehicles but they're holding off on those for now.