Just a bunch of combat. System Shock had more to it than just combat. So that's a big red flag right there.
Secondly it looks too pretty and that makes me worried about how much money was sunk into this because if they sunk a shitload of money into this chances are they are going to stray from what made System Shock what it is in favor of a far more streamlined approach. Which is another red flag.
And finally, as to the setting, really? I mean, is this all the series is going to be? New space station, same AI? I think I can predict what SS4 is going to be then, get this: It's a new space station, right? But... Everything has gone to shit and everyone's favorite character SHODAN makes a return!
I'm not trying to be a negative Nancy for the sake of being a negative Nancy, but I've seen far too many sequels fuck everything up. Every future sequel has to prove that they aren't a fuck up to me and this trailer doesn't bode well for it. Doesn't mean I've made up my mind yet that it is in fact going to be trash, but I see literally nothing to be excited about. Just pretty graphics and things dying with a voice overlaid on top by the villain. Never seen that in a trailer before.