The general concept is that the players on crew on a space mission and need to survive for 10 minutes. The style is cooperative - everyone works together and you win or lose as a group.
The 10 minutes are played out in real time and there is an MP3 describing everything that goes wrong: alien attacks, malfunctions, intruders, etc. The players than have to run around the ship and take action by playing cards from their hands.
After the ten minutes you look back over what each player did and then you get to find out whether you survived or not. There've been a few times that we thought we won but later found out that a damage prevented us from firing a crucial laser shot.
The ten minute real time phase is chaotic and demands high coordination and communication among the players; it's challenging and a lot of fun. The recap after is a little tedious by hand but luckily there's a great Flash application which resolves it all for you; there are even funny animations of your players running around.
I've now played it with 2, 3, and 5 players and on multiple difficulties; I'm confident in saying it's the best game I've played and perfect for any size group.
Links to the tools we used:
Flash Version of Missions (from the CD plus new random ones)
Turn Resolution Processor (for finding if we survived)