Despite the fact that Portal only has a shallow narrative, the quality of its storytelling makes it one of the best stories in games.
Portal is a game that isn’t about dialogue or narrative but is rather about exploring the world and discovering aspects of the game design. As you progress, you discover secret areas, graffiti and writing that hints that GLaDOS might have a sinister motive.
There is a genius to the characterization in Portal. The character development of GLaDOS, who goes from being a friendly robot to a diabolical force bent on destruction, is masterfully portrayed. She even manages to show some great sarcasm, at one point pretending that her attempt to murder you was a test.
Portal has a fantastic sense of pacing that keeps the gamer hooked, and thanks to its unique manner of storytelling, it becomes one of the most memorable games of all time.