Why would it cost less than a regular game when it allows you to make games that you can sell and make money off of? Most game engines or game creation programs of this level cost hundreds if not thousands of dollars so you should be grateful for such an excellent price. Believe it or not, considering the power you get, $70 is an unbelievably low price.
If you don't know what the features are, then take a look at their website.
http://www.fpscreatorx10.com/
A picture says a thousand words.
-- H.K. --
http://www.fpscx10-online.com/