Which type of plot is suitable for comparing two or more features of points at coordinates (x,y)

The title is quite difficult to understand so let me give an example:

points at coordinates (x,y): people at age x and with y as size of the city they grew up in

features: (1) yearly income, (2) number of work-related contacts, etc

I'm interested in studying the effect of (x,y) on these features. If I was only interested in one feature, say, yearly income, a colormap would be sufficient where the color at each location (age, city size) indicates income. But here I want to look at more than one feature.