It’s a bundle of a single game I like with lots and lots of discounted DLC.
The Colossal Collection contains all the expansions up through 2021’s Sunset Harbor.
So 16.22 is a pretty good discount.
Cities: Skylines Humble Bundle contains six years of DLC
The Cities: Skylines Humble Bundle offers the base game, 9 expansions and 21 add-ons for a fraction of their normal cost.
