When i first heard of the game, portal 2 was already out and i played that one first. Just because i am stupid to do so! Anyways! This game was really nice. Some of the tests were strange but not that hard. I loved how GladOS was trolling us all the way to the end. And don't believe her about the cake! In the game, you are supposed to be a test subject. They give you a gun that makes holes and you get through them. There are a few simple tests and a few harder tests that need timing or precision. It's a really good game. Just remember to pay attention to the lady that talks and never believe her!