In this game you have to return aliens to their home planet. At each level there is a green glowing rectangle, a portal, which is used to teleport the creatures to their destination. You can move the characters solely by physical laws, namely by removing objects that are located on the map. Remove the objects underneath the alien beings and they will slide further on the map toward other elements. Thus, there is a need to properly dispose of items. Since this is a game of logic, with many levels in which to think about what elements are to be removed at which points, you'll need to decide what time it is best to move or whether objects should be removed altogether. Good luck!