From GameWatcher: “Co-op shooter Generation Zero received a set of Challenges in its recently released September update. A first step in terms of giving players more to do while out in the world, each Challenge has several tiers with their own requirements and rewards.
Generation Zero Challenges are split into two separate trees. Where the Resistance tree focuses on eliminating machines, the Truth tree focuses more on completing missions and discovering what happened to the world.”
Source: N4G PC Generation Zero Challenges – What Are the Requirements and Rewards?