We all want to play with the toys we read about. All sci-fi universes (and many fantasy ones) include technologies like lightsabers or tricorders. We imagine or watch our favorite characters like Geordi La Forge or Luke Skywalker use them to explore alien worlds or vanquish evil foes. These devices create expectation, or "affordance," of what we expect would be possible within a game set in their respective universes. What exactly can’t a lightsaber cut through, anyways? The fictional world has its answer, of course, and many plot sequences rely on it.
Many single player games like first person shooters happily allow you to devastate the terrain with any number of weapons of varying precision. A number of versions of the BattleTech Franchise allow you to pilot a 40-100 ton BattleMech (a robotic tank). But when it comes to non-conventional uses of technology, you are often limited to the imagination of the programmer who implements them.
Take the use of special items in first person shooters. These items actually harken back to adventure games like Grim Fandango, where you need to find the exact location and circumstance to use them, and only then will they change the world. This is understandable, at least from a programmer's perspective: it eliminates all of that messy uncertainty as to what the player intends to do with something, and it preemtively constrains what the player can do.
This paradigm started to decay when Valve popularized physics-based gameplay and puzzles with its Half Life series. Now you could not only destroy something (display destroyed model, remove from world), but you could trigger trebuchets, you could see explosions push large objects down and crush whatever is beneath them. Destruction became fun. And you could use Half Life's primary gun (the gravity gun) both as a weapon and a tool to solve puzzles. It became an object of desire in its own right, born in a game and magnificently fulfilling its role as an operative tool in the game.
The lightsaber is not nearly so useful. I've yet to see a Star Wars game where I can use a lightsaber to cut through any given bulkhead and see what's on the other side. I've yet to see a Star Trek game where I can use the teleporter to teleport anywhere on a planet's surface. I've yet to see a game where I can cast a spell and truly control the effects to the level of precision that the song and dance often accompanying such acts would lead you to believe was possible. But these technologies, skills, and possibilities were not created in a game. Their use was not considered ahead of time by a game designer where limitations would have a meaningful impact on the entirety of the game experience. And so when these objects of power and technology appear in various games that sport the franchise brand, they are "nerfed" to fit into a more reasonable set of expected states. Like the inevitable walls that surround a level you explore, these limits are often invisible until you ask the ever burning question, "what if?"
Portal introduces a new object of technofetishism: the portal gun. A gun whose sole purpose is to create interesting limits and abilities for use in puzzle-like game levels, used as an indirect weapon and as a means of moving through space. For those who haven't played the game, play it. It is universally hailed as an achievement in game design--praise well deserved. You are introduced to the main technology as a test subject, walked through very simple scenarios where the ability to create two portals that link to one another is explored in an increasingly difficult and novel set of "tasks." Alongside these tasks is born one of the greatest malevolent and loveable sarcastic computer characters of all time: GLaDOS (Genetic Lifeform and Disc Operating System).
Portal Two maintains the core mechanic of linking spaces to each other, but introduces new characters and new objects with which to change the original boundaries. By the end of the sequel, you are fully aware of why it is you can do what you can do, what exactly it is you can do, and how to solve any puzzle thrown at you. It is truly a fine example of gameplay as learning experience, and a technophile's dream come true to be able to say: "What if I used this gun to create a portal here, jumped from there, and shot...?"
Can every game or fantasy world incorporate such an exploration of process? No, but the door to introducing the player to emergent gameplay experiences and respecting the desire to experiment and play with the in-game technology is opened. What game or universe will follow in Portal's deep and trans-dimensional footsteps?