From the video description:
Completely reimagining the classic Arena FPS formula, Chroma infuses fast-paced PC shooter action with music-driven gameplay. Join the fight as a Fader, a musical icon of the future, and battle for control of the all-encompassing cultural feed known as The Signal. Unleash streams of sound and music with your arsenal and bring the musical landscape to life in battle! Master multiple classes, each with their own unique musical gameplay mechanics and perks, and lead your team to victory.
Chroma is the upcoming PC game from Harmonix, the studio which brought you such hit video games as Rock Band and Dance Central.
If you want to try it out, sign up for the alpha here.