I can tell by your choice of cities that you're not super familiar with NJ.

For example, I was surprised to see "Franklin" as one of the cities. While Franklin Township technically has a higher population, it's far less well-known than neighboring New Brunswick which you excluded. New Brunswick is much more of an actual city than Franklin. It is home to Rutgers University, Johnson&Johnson's headquarters, several hospitals, a large performing art center, an Amtrak station, etc, etc.

Using the population alone in determining which are "Major Cities" in NJ is likely to leave you with a map of some large suburbs that aren't really the cultural hubs of the regions. (See also, Cherry Hill vs Camden).

There are also some culturally or economically significant cities that could be added, if you so chose. (i.e. Hackensack, Fort Lee, Morristown, Bayonne, Hoboken, Asbury Park, etc)

Cool game though!