In Killer 7, players take on the role of Harman Smith an unlikely assassin who lives life at his own pace. Switching between seven different personalities, he employs each character's abilities to terminate targets he deems "deserving to die."

Years have passed; violence and instability have started to beleaguer developed nations. People with crazed and distorted smiles are appearing throughout the world. Anyone with this 'Heaven's Smile' becomes violent and begins attacking anybody within close proximity. Now these crazed soldiers have started to overthrow huge city governments and have even taken the life of Harman's beloved Suzy. It is up to the player to utilize the special powers that dwell within Harman's seven 'partners' to assassinate the powerful underworld kingpin behind it all, Kun Lan.

• Distinctive and visually stunning approach to art-shaded environments
• Unique cast of playable characters – Each persona has different strengths, special abilities and powers that help Harman proceed through the game. The 7 personalities that comprise the "Smith Alliance" are:
  • Galusian Smith – The clairvoyant leader of the 'alliance' who has the power to envision an enemy's weak spot and can foresee various traps and scams
  • Dan Smith – Strong and skilled, Dan has the ability to change weapon trajectories using telekinesis
  • MASK De Smith – A gun wielding man whose masked appearance conceals his true identity
  • Coyote Smith – Has the ability to physically move through objects
  • Kaede Smith – The only female personality of the group. She is a very important pawn for Harman as her appearance reduces some of the risk of being an assassin.
  • Con Smith – A child blessed with exceptional hearing. He uses his ability to hear his enemy's pulse and ascertain their whereabouts.
  • Kevin Smith – An independent personality that keeps to himself. He holds the key to Harman's past.