Aftermath follows the formula of Stuffed Fables and Comanauts in that the game includes a book of scenarios that collectively form a large campaign, with 1-4 players working together to survive in an unfamiliar and hostile environment. Aftermath is due out in Q4 2019, and you read the rules now on the Plaid Hat website (PDF) or get started with this overview of the game:
In the game, you play as a misfit band of critters known by their colony as "providers". There's the guinea pig with anger issues, a hamster that talks fast and drives faster, a small mouse with keen eyes and a lot to prove, and a mysterious vole who's borderline feral. These characters each have their own personalities, play-styles, and personal goals.
You'll leave the safety of your colony and venture out into the abandoned world on one of 27 story-driven missions and side missions. Scavenge the ruins of mankind in search of food and supplies for your colony, but beware — the world is filled with bandits and predators, and you must fight or flee to stay alive.
Return to your colony with resources and information that will help your friends and family survive. Grow your colony and keep it safe by building structures and improvements with the spoils of your adventures, but plan accordingly, for the colony will face hardship each time you leave it...