In chapter 7 of “A Theory of Fun,” Koster listed many ludemes of a successful game: preparation, sense of space, solid core mechanics, range of challenges, range of abilities required to solve encounter, and skills required in using ability. Portal was an extremely successful game that artfully incorporated all of these ludemes to attract a cornucopia of players with a range of video game experience that was challenging to all. The preparation was the first few levels when you begin the game. It is very difficult to be killed in the first few levels where new skills are introduced and the player is familiarized with the game style. The sense of space in Portal is very interesting. It is obviously very limiting because the doors only open forward once the level is completed and the doors will not let open backwards. Because of the actual portals, space is distorted, but only for a short time until the player has acclimated to the new world’s game mechanics. Now onto the solid core mechanics of the game, the game has real physics in that gravity applies when you jump. The player can run in all direction and levitate things with its mind. The portal is the most unique thing to the game mechanics. Everything else is pretty standard. The range of challenges in Portal is spectacular. Speaking as a novice game player, Portal was extremely easy to pick up, but still was very challenging. Most of the puzzles involve logic; all that needs to be picked up are the game controls. Like I said previously, the first few levels are very easy, and progress showing more challenges. As the levels progress, they also introduce new abilities. I believe some of the first ones were: jump, pick up, drop, etc. and as you get further, you learn that the shiny ball of light needs to go into the receptor thing to open doors and such and that you can use the velocity from jump into a hole to project you further. Also, as the levels progress, more and more of these abilities are required to solve the problem. Each time the player uses an ability to solve a problem, their skill in that ability grows.
Portal also has a variable feedback system in which Koster says the result of the encounter should not be predictable. After each level, you are to enter an elevator so you cannot see what is coming next and usually what the mechanic female voice says is very bizarre, ironic, and unpredictable. In Portal, the mastery problem is dealt with in that the levels get progressively harder and you can save your levels to that you do not have to bottom feed. According to Koster, failure must have a cost. In Portal, there is a cost, but it is not too grand. For the most part you have to restart the level or you are set back to a saved point. Either way failure is more of an inconvenience than anything else. Portal uses all of these traits effectively to create a fun, challenging, and addictive game for all players.