Yesterday, Thomas Puha, Head of PR at Remedy, answered some queries on the NeoGaf forums about the Gamescom demo of Quantum Break and how what was shown reflects on the full game. With all game demos, only a small section of the game gets to be shown, so it can be challenging summarising the game in that time.
Topics which were discussed on the forums are the time powers and how challenging the combat will be. If you're interested in finding more about the difficulty in combat or exploration in the game, check it out HERE.
In reference to enemy difficulty and time powers:
We get a lot of feedback that it seems Jack is completely overpowered compared to the enemies. I can understand why the trailers give you that impression. In the Gamescom '15 demo (that we have not released online) the enemies are rather static for the simple fact that AI of those enemy types was not very ready at that point. I think it would go without saying that the final game will offer a real challenge.
There are a variety of Monarch enemy types you come up against. Some of them like the Strikers (and the Juggernaut you saw in the bridge sequence) have experimental Chronon technology which levels the playing field as it allows them to warp around as Jack does, and they really do now so, it's nowhere near as easy to kill them.
The players Time Powers have got cooldowns, which in demos were not in place, so of course in the final game, you cannot be Time Stopping all the enemies all the time. Don't worry.
Also, some people have commented how there is so much going on during action, all the VXF and such...of course that's not the entire game. There is a lot of just exploring, talking to NPC's and being immersed in the world...rest assured, we got a great balance of action, adventure and time breaking down craziness.