Space Maze Rollercoaster is a mini expansion that contains 3 'Rollercoaster' cards which can be added to the deck of action cards in the base game. You should choose whether or not you want to use it before every game, because it changes gameplay considerably. If you do use it, make sure that in your board setup the relic tile is not on the edge of the board.
Effect: Take a tile at the end of any column the alien activating the card is in (up/down or left/right) and place it at the other end. Now shove all tiles in that column one place further. Aliens on tiles always move with them, even if they're moved to the other end of the board.
Adding the card to the base game changes the way you play in a way that it becomes more funny and chaotic and maybe a little less tactical. Therefore it's advised not to just add the card to your base game as if it's just one more action card.
'Space Maze Rollercoaster' was a free expansion when you bought the game at Essen 2011.