Killing Cloud is set in a San Francisco ravaged by an opaque orange death smog layer known as the Killing Cloud. This hovers around the middle of the skyscrapers, creating a claustrophobic low level experience (and a different feel to the many other flight simulations set in the city, such as F/A-18 Interceptor).
In this maelstrom, the Black Angel gang is terrorising the public. The player is a member of the SFPD Police force, charged with bringing them down throughout ten missions. Some are out-and-out action while others are more strategic. You can only survive for 20 minutes in the smog, so time is crucial in these missions.
In addition to outflying the enemy on your hoverbike, the player must carefully pre-position ground forces to arrest him when he is brought down, using Pick-Up Pods. Once arrested, a suspect must be interrogated to release enough information to know what the next threat is.