Portal

Portal is a puzzle game from Valve Corporation that relates to Team Fortress 2, Half Life 2, Left 4 Dead 2, and Counter Strike.

Plot and Gameplay
The main protagonist is Chell who carries a handheld portal device that shoots both orange and blue. In the beginning, Chell wakes up in the aperture science laboratories as a newborn test subject, assigned by GLaDOS, however, Chell runs through the first set of tests. Without the portal device, she can't shoot portals. After the fifth test, she gets the handheld portal device that only shoots blue portals, a basic set of portals. Five more tests with it, one of the tests, involve a battlefield of turrets set by GLaDOS. Chell needs to avoid two tests with turrets. Then she finds a test that requires two dual sided portals (orange & blue) to do the deed. When she gets the companion cube to three platforms, out of her reach, then destroys the three turrets, and jumps across safely, she gets the upgraded handheld dual portal device. She needs about seven more tests. The tests just involve turrets and jumping for the most part. and she realizes to go far, GLaDOS sets a death trap for Chell as she falls in this fiery pit of doom, (a reference to Indiana Jones) Chell quickly reacts like Indy and escapes the pit and explores the pipe maze of glados, and does tests on her own customs. Then when she reaches the end, she finds GLaDOS. She takes about six or nine hits to defeat her, theirs the infamous "Still Alive” song that plays in the credits.

Rumors and the cake
No one knows if the "Still Alive" song will be in the sequel. there's a way to get to the cake, several YouTube videos have it so you don't have to be fighting GLaDOS in the final fight, you have to watch the ending cinematic where it shows the traditional "portal cake" to get to it. Apparently this is why, they commonly call the cake is “a lie." but no one says that the cake isn't a lie. The cake is just an award trademark of Valve Software's top quality.