buildworld selectively?

[Walter Hurry]

As a relative newcomer to FreeBSD I am planning a 'make buildworld' for 
the first time. Since this is likely to be a lengthy process (my first 
attempt will be in a virtual machine), I am wondering whether it is 
possible to be at all selective about what is built.

I have read the handbook section thoroughly, and shall follow the 
procedure recommended. I have also consulted 'man make.conf', but have 
been unable to establish an answer.

For example, I do not require 'games'.

Is there a way of achieving this?