Cataclysm: Dark Days Ahead is an open-source survival horror roguelike that immerses players in a post-apocalyptic New England. Unlike traditional roguelikes, this game allows players the freedom to explore a vast, procedurally generated map without a specific goal. Players can engage in various activities such as clearing areas of monsters, interacting with NPCs, and constructing shelters and vehicles. The focus is on managing survival parameters like hunger, thirst, and temperature, making every decision crucial for staying alive.

The game features turn-based gameplay and incorporates dynamic elements such as seasonal changes and weather conditions, which can be customized during world generation. Players will encounter a variety of environments, including cities, towns, and natural landmarks, each filled with familiar establishments. Unique locations like military installations and science labs add depth to the exploration experience. Recent updates have introduced experimental 3-D building support, enhancing the immersive quality of this expansive survival adventure.