Addictivity

The two-player option is brilliant (one takes control of the jeep and the other the helicopter) and increases the addictivity.

2004, Lowinson et al, Substance Abuse: A Comprehensive Textbook At any one time, 70% of smokers would like to be able to quit but cannot do so primarily because of the extraordinary addictivity of nicotine.

Apparently, with heroin-like euphoria and addictivity, it's taking over as the drug of choice for inner-city youths, as well as college students.