The game can be played for free as part of the free play weekend at Ubisoft.
Welcome to the 19th century. A century of industrialisation, diplomatic disputes and discoveries. Choose a path that will define the world. Are you an innovator or an exploiter? A conqueror or a liberator? How the world remembers your name is up to you.
The game will be fully playable from February 25th
to March 1st
(local time). Start your download of Anno 1800 right now and be ready when servers open.
Once the free weekend is over your progression will be carried over if you purchase the game.
Credit to @XiaomiTemple
for the initial find at MyDealz
Hope it helps someone.