Carnage Among The Stars is a brilliant game for Conventions or one-shot gaming. I have run this every year for last last 5 years at a local convention, using the incredibly simple mechanics to gets groups of 13 or so players to have a rip roaring good time. People who have never played ANY role playing game walk away saying how amazing it was and people come back year after year to play a new game in the crazy drak world of CATS. (Although to avoid religious connotations I call it Terran Revenge Fleet rather than 3:16. Right or wrong, religion in the US has an offputting affect on some players)
You can have a new player in less than a minute.
You can have people join a game or leave a game in the middle and lose nothing.
It has a lot of the feel of the Starship troopers movie, with seemingly endless swarms of enemies and limitless ammo.
After years of playing, we have some house rules like "You don't choose a name for yourself. One will be assigned to you by the other players as the game progresses" and some special rules to make the lives of the NCOs a bit more fun to play.
For $10 this is easily worth it and if you are ever in Minnesota for CONvergence, come play at the table! You'll walk away loving this game as much as I do.
[5 of 5 Stars!]