Transistor is Supergiant Games' follow-up to Bastion. The game features a talking sword that glows and pulses whenever it speaks to its protagonist. The development team was able to match DualShock 4's light bar color and pulse rate to that of the word; and they found that has added tremendously to player's immersion.
"When Sony revealed the controller, they suggested this light bar could have a variety of uses, such as visually distinguishing between four players in a cooperative game and stuff like that," creative director Greg Kasavin explained. "Sony didn't suggest it could be used to indicate when an extraordinary weapon of unknown origin was speaking to you."
"We soon found, however, that the light bar works really well for that. We got it to match the exact turquoise hue of the in-game weapon, and the flashing effect was in perfect sync. When I played with this for the first time, it felt a little more like the Transistor was right there in my own hands."
"The controller has a speaker on it, too," he added suggestively. "We're looking into that."