A City Sleeps is an indie action arcade game by Harmonix, officially released on October 16, 2014. Developed by the creators of Rock Band and Amplitude, the game represents a unique blend of music and gameplay, with a focus on creating an immersive audio-visual experience.

In A City Sleeps, players control Poe, utilizing twin-stick shooter mechanics while navigating through dreamscapes filled with enemies. The gameplay is intricately tied to an original soundtrack that evolves based on player actions, enhancing the overall experience.

The storyline follows Poe, a young dream exorcist from The Silk clan, as she ventures into the dreams of SanLo's residents to rescue them from a nightmarish slumber. Armed with her Koto-sword and ghost familiars, she must cleanse their dreams and uncover hidden secrets.

A City Sleeps stands out with its innovative Idol System, allowing players to possess inanimate objects for tactical advantages, and its music-driven gameplay that synchronizes level design with the soundtrack, creating a unique and engaging experience.