Kingpin is a Main Character in the game and gives Spiderman quests after the Tinkerer is moved into his building. The first time Kingpin is actually seen in the game is on the Bridge cutscene (The last time Spiderman is in New York when it's not in its apocalypse state is before this cutscene), when he demeands to know why the bridge has been shut down. There is a ending when Kingpin, Black Widow, and the Tinkerer assignSymbiote Wolverine to bring them Spiderman dead or alive. Kingpin can be found on the top of Kingpin Tower.
Glitches-
There is a glitch in a cutscene when there are two Kingpin's instead of one, one being the cutscene Kingpin, and the other being the normal interactive Kingpin.