15 Hours Played (Achievement) ???

[Lumabizz]

How does this achievement work?

Is it a total of 15 hours played on different gametypes?
Or is only one gamemode counted? (Exp: played 15 hours on easy)?

Im a little confused here, have finish the game on normal,
easy and hard mode, and still havent got the archievement.

(Have cheated a little on easy and hard, have just run through the game)

[Wreckon Dracgon]

First off I'd like to say welcome to the site.

Secondly I'd like to draw your attention to the SEARCH button.
In order to keep the forums nice and neat, cutting down on the number of pointless threads is key. So next time you have a question please search before making a new thread. This 15 hour achievement has been discussed in no less that four other threads. Including on the link attached below.

http://www.xbox360achievements.org/forum/showthread.php?t=23610