Portal is a first-person puzzle platformer originally made by Valve for Windows, PS3, and Xbox 360 (though it has since been ported to Mac OS, Linux and more recent consoles). Intended for a wide audience of anyone that enjoys spatial puzzles, this game revolves around the use of two-way portals to reach the exit of each level. Core mechanics include the bidirectional portals themselves, the player’s ability to place portals almost anywhere in the levels, and the conservation of momentum when passing through them. These mechanics create a profound experience of navigational freedom that contrasts well with the game’s oppressive storyline.
Fig 1: While the occasional violence in the game isn’t graphic, the red death screen following gunfire restricts the game’s audience to older children and up.
Fig 2: The first portals in the game, revealing their bidirectional passage to the player and their color scheme (orange and blue are independent ends of the same rift through space).
While we might take Portal’s mechanics for granted 18 years after its release, the bidirectional mechanic of the portals themselves was revolutionary. The game accordingly teaches this mechanic to the player gradually, as the player would presumably have no experience with this potentially disorienting mechanic previously. In order to leave the “relaxation vault” the player character apparently awakens in, the player is introduced to the game’s first portal: an orange ellipse on the wall that is connected to a blue ellipse outside the vault. Walking through the orange ellipse has us exit through the blue ellipse, and if we turn around and enter the blue ellipse, we return through the orange ellipse and end up where we started. This firmly establishes that the portals are bidirectional and form a direct pathway between two locations that aren’t actually connected. After passing through a quick test chamber where we place a weighted cube on a button to access the exit, the player needs to navigate a chamber with a fixed orange portal and a blue portal that changes locations, revealing that these portals don’t have to be fixed: one can change locations while the other stays the same. Only later does the player finally acquire the portal gun, which allows them to place an orange and a blue portal on any compatible surface (some surfaces like black tiles are un-portalable). While it quickly becomes clear that the player is a prisoner forced to complete test chambers by a malevolent AI, the bidirectional mechanic of the portals and the ability to place them at will creates an immense experience of freedom. Similar to how mirrors have the cosmetic effect of making a space appear larger, moving through portals makes even a small test chamber feel roomy as we can endlessly run through a hallway of portals on opposite walls. Beyond literally opening up the barriers of the test chamber, the portals make every space feel much more open. While conventional first-person platformers can feel cramped with only one proper route through, placing and moving through portals is liberating, and allows areas to be accessed in different orders and regardless of proximity. It’s hard not to smile when you can walk or jump through the walls that so normally constrain video game levels.
Fig 3: These icons on the floor help visually explain conservation of momentum to the player (and that you can leverage it to fly across the stage).
Fig 4: Falling through the floor lets you achieve terminal velocity! Whee!
A critical mechanic that builds on the freedom provided by the bidirectional portals is the conservation of momentum. That is, the player character’s speed is not slowed when they move through a portal. Once the player obtains the portal gun, they’ll be tempted to place a portal above and below them and see what happens. If they do this and jump in, they’ll keep accelerating until they reach terminal velocity. Then with a well timed replacement of the top portal onto a horizontal surface, they’ll fly across the level, retaining their built up speed. Similarly, if the player places two portals on the ground and jumps into one of them from higher up, they will shoot up through the other portal, slowly decelerate, fall back down, and then shoot up through the first portal, and so on. By building up speed and using the right timing and portal placement to soar through the level, the player’s movement becomes much more unshackled from conventional platforming. The same mechanic that lets you walk through walls also lets you fly! And thanks to a lack of fall damage (explained in-game with spring implants that you can see attached to the player model), you don’t feel overly penalized for missing a jump. While you can manage to kill yourself by hitting the floor at terminal velocity, but doing that is tricky and doesn’t much negate the high-mobility dynamics.
Fig 5: Hmm, it looks like GLaDOS has decided to kill me.
Fig 6: Haha, I portaled out of the fire no problem. Get wrecked, GLaDOS.
Fig 7: Payback time! The player character, a prisoner, can fly all over the place, but the AI antagonist GLaDOS is just stuck there, hanging from the ceiling. Ironic!
As the player progresses through more chambers, the story is revealed to be more and more oppressive, but the player simultaneously becomes more skilled at placing portals and building up momentum to navigate the worsening hazards. Some levels have a lethal sludge, some have homicidal turret robots, and eventually the AI antagonist, GLaDOS, directs you onto a moving platform meant to dump you into an incinerator, having apparently gathered all the data it wanted from you. Quick thinking allows the player to flee through a portal and escape the gauntlet of test chambers altogether, taking them through the bowels of the research facility. Entering spaces the player character was never meant to be tested with helps compliment the player’s developing sense of spatial mastery. The evil AI has failed to contain you and now you’re feeling unstoppable as you puzzle your way out of the facility. A final boss fight against GLaDOS requires the player to put all their skills together, resulting in them dancing circles around it. While the player character is a prisoner, the antagonist is ironically immobile, just a big robot arm thing hanging from the ceiling during the final stage. When completing this challenging final showdown, the player should feel like they’ve mastered the game’s spatial thinking and aerobatics as they turn the tables on their enemy with their radical freedom to maneuver.
Portal is often considered one of the best video games of all time, and for good reason. Its core mechanics of portals and momentum make the full three-dimensional extent of each level much more open than the levels in many other puzzle platformers, and the novel dynamics these mechanics create are highly effective. The difficulty steadily rises, but only as the player themself becomes more skilled, ending with a satisfying test that proves they can truly think with portals.
Ethics
As discussed above, Portal does a good job of introducing the portal mechanics to the player during the first few stages and assumes they have no familiarity with them. During the very first stage when the player awakens in the relaxation vault, the movement controls (WASD and space bar to jump) are displayed on the screen, making sure the player doesn’t get stuck before they even enter the first portal. So even if this was a person’s first 3D video game, they should still be able to understand the game’s controls and mechanics. The specific requirements for completing levels (such as placing cubes on buttons and not touching toxic sludge) are always explicitly narrated by the antagonist character, and subtitles are available in case the player doesn’t have speakers or has hearing issues. This doesn’t leave much room for the player to be confused about how the game works, only room for healthy confusion about how to solve a particular level.
The only pre-game knowledge the player is assumed to have is probably an understanding of at least one of the game’s languages and the ability to navigate to the options menu to change the language if they need to. While the game has a lot of languages available, it is missing four of the top 10 most widely spoken languages (Hindi, Arabic, Bengali, and Urdu) meaning speakers of those and other unsupported languages, amounting to billions of people, are potentially excluded if they cannot access a third party mod to support them. I won’t fault Valve for not including every language in existence with the initial release, but it would have been cool if they had updated it with even more languages over time, as they certainly have the money for it!
It could be argued that the game also presumes knowledge of basic user interfaces and what it means to save and load their game, which might be confusing if this is the first video game the user has ever played, but this presupposition is in no way unique to Portal. A bigger barrier to entry would probably be the game’s nonzero price. As a fairly old title, its $10 price is frequently discounted even further (I think I remember seeing it at just $1 on Steam before), but even that much money could be much better spent on necessities depending on one’s situation. Though if someone has access to the internet and still can’t afford it (or access an online payment system required by Steam), I can’t imagine that pirating it is too difficult.
