no, the game can be whatever is NOT illegally used in conjunction with the FPSC. However, he means that you can't 1) sell any custom stuff seperate that is not your own or provided with a license that say please sell my custom made stuff as your own license, 2) you cannot sell the FPSC program (meaning what you made it with or editor as some call it) and 3) You cannot alter any of the files from the source, stock media, or any of the above (both) and then redistribute as if your own.
Basically you bought FPSC, and can sell what you make with this (as long as its your own work game, content, etc) anywhere, anytime, to anyone that wants to buy it. You paid $50 for an engine, editor, and stock media to do with as you please while using it for and only with the FPSC.
TRANSLATION: Sell your games anywhere that you make using the FPSC.
Sign here...