In Terraforming Mars Ares Expedition: Crisis, players play as corporations, just as in the original Ares Expedition. You select phases and play project cards as normal. The difference is players are working together to keep Mars habitable after a natural disaster has thrown the planet into crisis. Each round, a new Crisis card will be drawn that will require the players to achieve a certain goal to remove that crisis from play. Every turn that a Crisis card is not completely dealt with, it will lower one or more of the terraforming metrics that keep Mars habitable.

Handle all the crises as they arise. Eventually, a Crisis card will be drawn that lets the players win the game once they have completed re-terraforming Mars.