On Mars: Alien Invasion is the much-anticipated Somewhat Cooperative Expansion to Vital Lacerda’s best-selling and highly-rated On Mars base game. Though this expansion was originally going to be named Surviving Mars, Eagle-Gryphon Games made the decision to change the name to On Mars: Alien Invasion to better reflect the theme and content of this expansion. The game narrative is contained in four chapters of a story written by Nathan Morse. Gameplay contains four new and different ways to expand upon and play the base game. You will play one versus many; completely cooperatively; and even solo if you wish, depending on the chapter. Included are four fresh and completely replayable ways to establish colonies On Mars!

For instance, here is the narrative that opens the first chapter and sets the stage for all of the following action:

—description from the publisher

On Mars: Alien Invasion is a short story expansion to On Mars made in 4 chapters with 4 different modes of play.

The short story is called Alien Invasion and contemplates the following Chapters and modes of play:

Chapter 1 - Invasion - 1 vs All - 3 to 5 players
Chapter 2 - Outbreak - Co-Op - 2 to 4 players
Chapter 3 - Blackout - Co-Op - 2 to 4 players
Chapter 4 - Monolith - Solo - 1 player