It's the VR and the cooperative multiplayer aspect coupled with experiences that cannot exist in the real world.
A sample:
They had me at 4:15
It's still some time away from being as smooth, polished and feature laden as the megagames we have today, but I can imagine the tech in 10 years; you come home from work on a Friday, feed the cat, turn off the phone, lock the door, and strap into your VR head gear and join your crew for a couple of days of interplanetary adventure. It's going to be great.