Evil aliens try to destroy our world and you have to stop them. Nice use of portals and gravity in this game. You can also use your spirit form to run around and it is used to solve some puzzles.
Here I write what I think about the games I have played. The score is shown as a smiley before the title of the game.
Note about Movies: None of the Youtube movies that i link to are made by me and i include them only to give you a chance to see what the game looks like. Only the text and the smiley score act as my review of the game .