You’re in the basement of an office complex. The power is out. Your dim lantern lights the way. You don’t know how to escape, and you’re not alone — there’s some sort of monster down there with you.

You shine the beam of light over a sign that reads “Lab SB-132” and a voice crackles over your headset: “Wait, stop there. Go down the hallway to your right and take the last left.” You head down the hallway, but in your disorientation, you can’t remember if she said the last left or the first. The growls are getting closer.

The game is called Fear Sphere, played entirely using the lantern in your hand. The beam of light is created by a pico projector housed in the lantern body, and its orientation is determined by a six-axis accelerometer.

The only thing you can see is the small circular projection onto the inside of a pitch-black sphere, like a flashlight in a dark room. You can call out your location to a friend outside, who has a map and can help direct you, but it’s easy to get panicked.

Matter Over Mind

When you think of a game controller, you’re likely picturing a shapely lump of plastic, with two easily graspable lobes, two joysticks, and as many buttons as can be placed within reach. You probably don’t think of a pile of sand, or a cardboard box, or an endless loop of carpet on a treadmill roller.

alt.ctrl.GDC is a showcase at the annual Game Developer’s Conference that explores alternative interfaces for interacting with games. It started as an award category in the Independent Games Festival, but as entrants grew, it became clear that these unique games needed a home of their own. Shepherded by John Polson, alt.ctrl.GDC is now in its fourth year, showcasing custom-built hardware and software to create unique player experiences. “We spend a lot of time thinking about how video games touch us,” says Polson, “alt.ctrl explores how we touch games.”

Imaginative Engineering

Unsurprisingly, microcontrollers like Arduino and its endless variants are the brains behind many of these interfaces. Numerous commercial game engines, like Unity and Unreal, provide an API that allows Arduino to interface directly with the engine as an input/output device. Events in the game can trigger anything from an indicator light or movement in a physical gauge to kinetic interactions like activating fans or blaring klaxons. And for input, the only limit is whatever the creator can imagine and engineer.

Take SpaceBox, a playful and childlike spaceflight simulator that you control with a simple cardboard box. You lean forward, back, left, and right to steer the ship. Designer Robin Shafto wanted to recreate the imaginative worlds of Spaceman Spiff, Calvin’s spacefaring alter-ego from the Calvin and Hobbes comics.

Buttons mounted underneath the box detect the direction you’re leaning. To raise your shields, you lift up the left and right flaps of the box lid. These movements are detected by accelerometers, and the ship’s blaster is a simple conductive button built from a lip balm tin. The colander you wear as a helmet might just be for looks, but the experience wouldn’t be complete without it.

Not every solution needs to be high tech. Zombie Crawler lets the gamer play a zombie crawling down a hallway to reach the tasty human at the end. To do this, players drag toward them a loop of carpet on treadmill rollers, occasionally slapping at green buttons on either side to smash obstacles out of the way. When the human takes aim with the shotgun, the player can rock the treadmill from left to right to dodge.

The movement of the carpet is captured by a computer mouse’s optical sensor, and the tilting movement is recorded using magnetic reed switches. All of these inputs are captured using an IPAC board, a computer interface card popular with home arcade cabinet builders, which is an easy solution for folks who want to spend more time on their hardware design than their Arduino code.

Enhancing the Experience

While some projects are created just for the experimental whims of the teams behind them, others come from universities, like the Game Design and Graphics program of Uppsala University in Uppsala, Sweden, where alternative control schemes are part of the educational curriculum.

There’s an annual alt.ctrl game jam with gathering sites in 11 cities around the world. Some creators, like Gregory Kogos (of RotoRing, a simple interface with two Adafruit NeoPixel rings and an Arduino) are developing their alternative control games with the intent to launch a commercial product. Likewise, Objects in Space is a trading game augmented by an open source control interface powered by Arduino. You can play the game without the extra control surfaces, but let’s be honest: launching torpedoes with a toggle switch is always better than a mouse click.