This game works off the premise of game kill streaks in that they advance the players skills (e.g damage, movement) momentarily. The idea is formed based on the movie CRANK (2006), as the main character is unfortunately placed with a faulty heart that requires adrenaline to survive. The player is dropped in different maps populated with enemies (random gang members) that he must take out in consecutive action to obtain a fast paced and steady killstreak. The killstreak pumps the player with adrenaline so they are able to move and move faster with each consecutive kill. The adrenaline prevents the player's heart from giving out and their ultimate death/end of game. In this instance, with each killstreak the player gains faster movement, higher damage, and more agility to prevent draining as much stamina.
The game is a singleplayer shooter (almost arena like) game that places the player in randomly generated warzones in environments of all gang related settings such as mansions, carparks, ghettos, or even suburban streets.
Here is a first person image containing a GTA SAN ANDREAS mod that represents the visual appearance of Killstreak
http://blog-imgs-48-origin.fc2.com/a/s/h/ashslowgameblog/gtasaimage02706.jpg