Portal is known for its humor. Even years after it's been out in the world people are still quoting and referencing it in everyday situations.

Throughout both Portal games there are hints left in various forms that fill in more of the story, including information about Chell's personal history.

The main mechanic of the game revolves around solving different puzzles using a handheld portal device - a device that can bend space and time to create a wormhole through which you can move.

The game made people emotionally attach to The Weighted Companion Cube and feel uncomfortable when later forced to incinerate it.

GLaDOS, or Genetic Lifeform and Disk Operating System, is the main antagonist of Portal games. She is voiced by Ellen McLain with the voice later processed to sound closer to how a text-to-speech program would synthesize a voice.

GLaDOS initially functions as a guide to the player and is only later revealed as a manipulative, narcissistic, sinister and passive-aggressive character that wants to kill the protagonist.

GLaDOS is the main force that moves the humorous yet dark narrative of Portal series with her remarks being simultaneously hilarious and terrifying.

Getting to the halfway point in Portal will unlock challenge maps and finishing the main story will unlock advanced chambers.