When Anno 1602 was published in 1998, I bet nobody outside the German-speaking market had ever heard of Max Design. They had some minor titles before, such as 1869, Burntime or Der Clou - but again, most likely unknown to any non-German player.
All that changed with the release of Anno 1602, which was a complete surprise blockbuster, both commercially and critically acclaimed. It eventually turned into a franchise that is still alive today with its most recent release, Anno 117, last year.
So, what makes Anno so great? For its time it showed incredible attention to detail: excellent graphics (for a business/management/strategy sim), the genre-typical and wonderful music, and above all a highly addictive “just one more minute” gameplay - seeing your empire grow through colonization and trade. While a military aspect exists in Anno, it is secondary at best.
The game had what we call “Wuselfaktor” in German. Loosely translated, I would describe it as the joy of managing the small things, being happy about tiny improvements, and seeing growth and progress. Other games such as Sim City The Settlers had that Wuselfaktor too.
One of the best games ever - one that just felt full of love for the small things and full of soul.