The Humble Monthly Bundle is a $12 subscription service that instantly gives you access to one game, and then a whole bunch more once the next month rolls over. Back in December this 'one' game was a combination of Quantum Break, The Long Dark and Dawn of War 3, while this time around you're looking at the time-devouring champion Civilization VI and two of its DLCs (Australia and the Vikings Scenario Pack).
Civilization VI definitely has some problems, and I would even go as far as to say that it's slightly inferior when compared to Civilization V and all of its DLCs, but even so it's still a fun game and for $12 it's probably worth giving it a look. This goes doubly so when you consider there will also be a whole bunch of other games joining the party at some point in early February.
Before you jump in, it is important to reiterate that the Humble Monthly Bundle is exactly what it says on the tin - a subscription service. So if you aren't happy with February's offerings, make sure to unsubscribe as soon as you get your bonus games, just to be on the safe side. And with that little warning now out of the way, I wish you the best of luck with resisting the urge to play for "just one more turn"... all the way till 4 am!