We've seen 1993's Doom running (slowly) on an E Ink display, but this is a new one. A team of indie developers got together at an arcade jam hosted at the London Hackspace and modified an old $48 upright piano to work as the controller input for Doom.
According to team leader David Hayward, the group used three I-PAC controllers to let the keyboard communicate with the PC running the game and covered the piano hammers with copper tape, soldering the piano strings to a common ground. A whole mess of wiring later, and the piano keys work to control the game.
We suspect one would have to know their way around a piano to play the game effectively, though. As you can see in the Vine below, player (and producer) Marie Foulson seems to know what she's doing without looking at the keys, but if you're used to the rather more compact QWERTY keyboard, you might be in trouble.
We can't tell if the markings delineating which keys control which actions mean you can just use any key in that section of the keyboard, or if specific keys are tied to specific actions, although having the black key front and center as the firing button seems to be a smart move.
Anyway, take a look at the game in action by clicking the Vine below. And don't forget to turn the sound on (we're not sure if the resulting ditty will be winning any symphony awards any time soon, however).