Changes

'''Half-Life''' (stylized ''HλLF-LIFE'') is a series of first-person shooter video games that share a single science fiction alternate history. The games in the series all utilize either the GoldSrc or Source engines and are linear, narrative, single-player titles.

'''Half-Life''' (stylized ''HλLF-LIFE'' only first game of series or just '''λ''') is a series of first-person shooter video games that share a single science fiction alternate history. The games in the series all utilize either the GoldSrc or Source engines and are linear, narrative, single-player titles.

'''Portal''' is a series of first-person puzzle-platform video games developed by Valve Corporation. Set in the Half-Life universe, the two games in the series, Portal (2007) and Portal 2 (2011), center on a woman test subject, Chell, forced to undergo a series of tests within (now abandoned) the Aperture Science Enrichment Center by a malicious artificial intelligence computer, GLaDOS, that controls the facility. Each test involves using the "Aperture Science Handheld Portal Device" - the "portal gun" - that creates a human-sized wormhole-like connection between nearly any two flat surfaces.

'''Portal''' is a series of first-person puzzle-platform video games developed by Valve Corporation. Set in the Half-Life universe, the two games in the series, Portal (2007) and Portal 2 (2011), center on a woman test subject, Chell, forced to undergo a series of tests within (now abandoned) the Aperture Science Enrichment Center by a malicious artificial intelligence computer, GLaDOS, that controls the facility. Each test involves using the "Aperture Science Handheld Portal Device" - the "portal gun" - that creates a human-sized wormhole-like connection between nearly any two flat surfaces.