A playthrough of the game is expected to last between 25-40 hours, as in addition to the massive story quest there are 10 optional secondary quests that can be completed. Don't expect to be sent on any frivolous errands though, as according to Sylvain "we really wanted to get away from this 'bring me three wolf pelts' or 'find us a mushroom'." Secondary quests will be big and all of them have an impact on the main quest, and - like the main quests - the story will branch based on your decisions.
Stealth will come into play as a key to making progress. We saw a section in which Mors utilised his 'skinchanger' ability to take control of his dog, which was then used to explore a new area undetected. By avoiding being spotted by the guards you can perform sneak attacks to take them down silently, and by approaching groups you can overhear conversations to gather information to help decide your next step.
Then there's the combat, which Cyanide reckon will feel like an action game with strategy elements. To achieve this you can slow down time during combat, then switch between each of the characters under your control and bring up a list of special abilities. After that, you'll have the chance to queue up as many as three attacks for each character and designate which enemies to use them against - then watch the attacks play out in real time. Each attack has an energy cost, so you need to think tactically and plan ahead to take enemies down.
One thing is clear: the team working on the game are all big fans of the books and TV show, and are desperate to live up to the quality of what has come in print and onscreen. With George R. R. Martin overseeing all aspects of development, it should - at the very least - feel like it belongs to the world. Winter is coming...