In the unsurprisingly scientific and meticulous fashion that is characteristic of Valve, the goal of every obstacle in Portal is quite simple – to teach the player about the obstacles ahead, and reinforce them as often as possible. This is largely apparent in its incredibly methodical level design and arrangement, emphasis on reinforcing lessons, as well as control of information.
Firstly, the game makes sure to only introduce new information one feature at a time. This has proven to be especially important due to its especially abstract game mechanics, and to not overwhelm the player. Truly taking this philosophy to heart, the first obstacle challenges the player to walk through a portal in order to grasp its most basic behaviour. After testing the player in their ability to weigh buttons with cubes, walking through portals and jumping on separate occasions, the game will then test them in combination. Furthermore, the player is not even able to progress until they demonstrate a firm grasp of these rules at a variety of skill gates during the game, ensuring that the player is never left unprepared for a puzzle.
To supplement this, these lessons are continuously reinforced to ensure that player’s don’t forget what they have learnt. This is evident when the player must accomplish a variety of puzzles before even retrieving the second, orange portal, after which they are forced to accomplish a similar design using their newfound skill.
In addition, the codification of their levels are used to implicitly indicate key information to players. The consistent use of dark, sloped walls to contrast the sterile white of the world imply that they are no place for portals – something that is instilled time and time again. At the same time, checkered tiles become synonymous with ideal portal placement.
The placement of props also serve to exist as hints. For example, the inclusion of the radio in the very beginning of the scene demonstrates to the player that the source of music is not occurring as background music, but rather from the prop itself. This association between audio and prop is drawn upon later in another level, where the deliberate placement of a radio is used in teaching the player about the purpose of the Material Emancipation Grill.
Accompanying the puzzle design itself is the strong cohesion of the voiceover and narrative, which provides both humour and hints at times. For one of the more abstract concepts of ‘flinging’, the voiceover makes sure to constantly hint at the word ‘momentum’, even to the point of describing the phenomenon as ‘speedy thing goes in, speedy thing comes out’.
The careful introduction a game’s features are incredibly important to games, and especially for those as abstract as Portal. It can’t be assumed that players will immediately have a grasp on features like portal transportation, and thus the developer needs to prepare them accordingly. Whether that is through proper pacing, consistent design or just clever writing, Portal provides a quintessential example of using seemingly-experimental methods for a seemingly-experimental game.