I know that there are a couple of XCOM/XCOM2 fans in here so this should make them happy.
- Chosen: enemies that get more powerful as the game goes on;
- Different kinds of Chosen with unique abilities;
- 3 factions: Players need to recruit them to your cause resulting in access to super powerful classes;
- The Lost: a new zombie-like enemy moves in swarms and attacks everything - you and/or the enemy;
- August 29th 2017;
EDIT: Additional info from the interview at E3 after the trailier - from reddit:
There was a short interview right after at the PC show. There are going to be 3 new alien enemies (shown in the trailer) that we’ll fight over time and who will get stronger each time. The three resistance factions will have to be wooed in order to get them to help you. The zombie like things are a new type of enemy that will appear in some missions (wasn’t clear which), which will fight both you and ADVENT.
The three resistance factions are a stealth/sabotage oriented group, a group of ADVENT defectors who are individually tough, and then a group of psionic adepts who will have attacks that will build up power over several turns for big effect.