As the title says, achievements for the expansion are unveiled. 

Here are some that caught my interest:

Xerophobic

As Morgawr, win the game without ever building or purchasing land units (except for Settler units).

Go back to R'lyeh

The Great Old One

The Grim Wave

Win a game with the Morgawr.

Facility Completionist

Control each of the unique facilities across any number of playthroughs.

Maritime Myths

Complete 5 quests for the Fomorians in a single game.

It Came from the Deeps

Attack an army containing only land units with an army containing only submersible units.

By Any Means

Complete your control of an ocean by trading for a Fortress.

Now, just to wait for it to actually come out... Between this and Endless Space 2, I don't know where I'll find the time.

For a moment there I thought we already have the steam page for it... but sadly no. Oh well. :P But why not mentione:

United Empires

Win a Shared Victory.

This looks... interesting.

Go back to R'lyeh

The Great Old One

Probably to do with the sea monster. Really interested in the share victory. Could be interesting for a 2v2 mp