This is the full list of features:

- Adds a new local strategic resource "Ancient complex", and a two-level building to exploit it.
- Adds a new policy to change what resources you get from those buildings, and factions demands for each policy option.
- Adds two civics for standard empires ("Archaeologists" and "Stellar ascendance"), which allow you to build powerful buildings in planets with "Ancient complex"
buildings.
- Adds a new option to buy ancient weapons caches to the trading enclaves, boosting your navies' and armies' damage (requires Leviathans Story Pack DLC).
- Adds a new ascension perk that lets you show proper respect to Fallen Empires, boosting their opinion of you and your research speed.
- Adds new museum buildings to let you share the gadgets you obtain from the Ancient Complexes with your citizens, and obtain several boni.
- Adds a new ascension perk that lets you build a "Galactic vault", in which you can store for posterity those gadgets, obtaining up to a 5 monthly influence and
20% research boni (requires Utopia Expansion DLC).
- Adds a new civic for Machine Empires, "Ancient Robots", which transforms allows you to reclaim the galaxy you once ruled (requires Synthetic Dawn Story Pack DLC).