That was strangely in slow-motion.
The interface is very 'X-COM', but the speed the Aliens were moving at makes me wonder if it'll be like the 'Battlestar Galactica' RTS, where you play through a game at one speed, but then the mission is replayed in a cinematic way. The AI chooses the best camera shots and tracks stuff of interest going on.
Which, honestly, would be truly amazing and superb for this.
In the case of BSG, it's turn-based, then the cinematic replay occurs and you have controls over how to rewind and view it. In the case of this, perhaps it plays out in slow-motion (to prevent the player feeling overloaded and simulate how a real person in that situation would have better reflexes than we would do), then replays the entire thing with cinematic perspectives.
If that's what they're doing it wasn't something I anticipated, but could be an ideal gameplay style compromise.
And if not, then they should do! Because now I've thought of this, it feels like a great possibility.