"Lifeline"'s selling point is its advanced AI system and the ability to direct Rio through the game via the USB headset peripheral. The player is given no direct control over Rio during any course of the game. Instead, the headset's communication aspect is utilized to its fullest, by giving the player the ability to use scripted commands, outlined in the game's various menus. While holding the input mic button (the O button on the DualShock controller), such spoken commands include "hurry", "Stop", "dodge", and "turn left", which cause Rio to perform certain actions and progress throughout the game. Rio can understand up to 500 verbal commands.