That's so odd. Especially since it says "Games For Windows" right on the retail box.
Games for Windows and
Games For Windows LIVE are two different things.
Games For Windows means that the game is made to run on a Windows operating system. More and more games are starting to display the logo and only a portion of them use LIVE.
Games For Windows LIVE support is denoted by a little blue LIVE icon in the bottom right of where it says Games For Windows. If it doesn't say LIVE then it doesn't use GFWL.
And also the X360 achievements count.
Do you mean the Xbox360 achivements count towards Xbox LIVE score? Well, they will do since the console version does use XboxLIVE.