: We’d love to get your feedback on Call of Duty: Advanced Warfare . If you
: would like to participate, please follow the link below which will direct
: you to an online survey. The survey is about 20 questions and should take
: 5-10 minutes to complete. In return for your time you will be entered into
: a sweepstakes for free Microsoft software (including games!). Please note
: that the survey is only open to US residents 18 and over.

: If you took this survey last month you are welcome (and encouraged!) to take
: it again. We'd like your feedback, even if your opinion of the game has
: not changed!

: Thank You!"

: So what, this survey program isn't just about Halo anymore?

There are a couple different survey programs that MS does. One is a general Microsoft Studios User Research one like you just got (Which covers multiple different titles and whatnot). There is also a separate one for the Halo Community Feedback program (obviously halo related). The subject of those emails generally lets you know which program is asking for your response.