Challenges are a game mode where the player must accomplish a specific objective within a time limit. Mission parameters, game rules and colony coordinates are predetermined and unique for each challenge.
Each challenge is set on specific map coordinates, with a particular sponsor and game rules. If you are attempting a challenge, you are playing under the same basic conditions as any other player.
Each challenge has a time limit to be "completed" - you will fail if the objective is not completed during this time. If you manage to finish a challenge in about half that time, it will be considered "perfected". While completing some challenges can be a significant feat on its own, perfecting them is balanced to be a challenge. The player is free to continue playing the map as a normal sandbox game after the challenge has ended, even if it was failed.
There are three different challenges for all sponsors, except for "Paradox Interactive" and "International Mars Mission".
No Mysteries are active during the challenges.