It looks like Ubisoft is trying to get more people on to their store as well. As we saw Epic Games is giving away Subnautica and a game every two weeks in 2019. Ubisoft is offering Anno 1602 for free for a limited time.
The game will be available for free on Uplay till December 23rd. The game definitely is a classic, being released in 1998. Buy since it is on the digital platform it does mean support for modern operating systems like Windows 8 and 10.
All you have to do is have a Uplay account and add the game to your library and it is yours.