Differences between Portal and Portal 2

This page is a list of all the differences or similarities between the games Portal and Portal 2. Should you find anything not listed here and of enough importance, do not hesitate to add it here. If a fact's deletion is deemed reasonable, it may be removed.

Due to the immense amount of data discovered during a playthrough of both games, this page is spoiler heavy.

Similarities

• Both Portal and Portal 2 are set in the same area and in the same universe (along with Half-Life).
• Both games feature a similar storyline - an opening sequence of waking up from stasis, going through tests and later escaping the testing track and sneaking through maintenance areas. However in Portal 2, that storyline was greatly extended by chapters 6 and 7 (The Fall and The Reunion) and then, in chapters 8 and 9 (The Itch and The Part Where He Kills You), the "test-escape-bossfight" storyline from Portal was used again.
• In both games (reduced in Portal) are some "timeline" levels that tell the player about history of Aperture Science. In Portal, it's the Escape levels, with claustrophobic offices and maintenance areas in extreme disrepair. In Portal 2, it's the levels of the aforementioned chapters 6 and 7.
• Both games feature the same protagonist.
• Both games feature the same antagonist (in Portal 2, only until the end of chapter 5, The Escape, when GLaDOS was replaced with Wheatley. However, it doesn't change anything about the fact that the antagonist is the Central Core.)
• Most testing elements (such as the Weighted Storage and Companion Cubes, Sentry Turrets or Super Buttons) are the same in both games.
• Both games feature backstage areas known as Rat Man Dens.

Differences

• In Portal, portalable walls are made of concrete blocks and non-portalable walls are composed of small brown metal cubes. In Portal 2, both types of walls are made of an unidentifiable material resembling plastic, although probably also composed of metal, as seen in broken panels of chapters 1-4 (The Courtesy Call, The Cold Boot, The Return and The Surprise) and while walking through the maintenance areas of chapter 5.
• The maintenance areas were significantly revamped.

• In Portal, all maintenance areas are claustrophobic and creepy crawlspaces in a state of serious disrepair. In Portal 2, maintenance areas are spacious, composed of catwalks circling the test chambers, which are, at this point, revealed to be large rooms on rails, so they can be transported anywhere, as the player was told by Wheatley in chapter 8.
• The Turret Manufacturing underwent a major change. In Portal, it was a few small rooms with unfinished turrets standing around, occassionally transported by crane arms of some kind. In Portal 2, the Turret Manufacturing is a large section of the Enrichment Center, probably taking up tens or hundreds of square miles. Boxes are piled up everywhere, sometimes arranged as walls, sometimes just thrown at a pile of some more, all either containing turrets or building them, as seen at the bottom of Turret Manufacturing in chapter 5. Near the same building boxes is a long line of metal sheets that later are cut into a grid containing all the parts of a turret, resembling real-life plastic models with plastic grids joined to parts of the final model. The Turret grids are sent by Multitasking Arms into the aforementioned building boxes.

• At many times while playing Portal, the player may see extended pistons that are used to move test chamber walls. In Portal 2, pistons are replaced with Multitasking Arms with the exception of Victory Lifts, which only had their model changed. However, pistons are still used, though very infrequently, and only in a level in Chapter 7.