This achievement requires paid content.
To obtain this achievement, you need to unlock 10 Time Spender medals. Time spent playing the game is cumulative, so you do not have to do this in one play or even one day. Bronze, silver, and gold all count (Once per game)
This type of medal can be earned in ranked or classic play. It can only be earned in games that you either own, are purchasing sessions with using the 40 MS point option, or on games that your console is licensed to (i.e. Someone else bought that game on your console). Medals can NOT be earned in demo play, or if you are using tokens to play a friend's machine. An added note, time spent in demo and using tokens is counted, but if you go over the goal the medal itself will only unlock if you play it "for real" (purchased game or purchased a single play)
A chart of which games have which medals available, and the goals that must be met to get those medals is posted here:http://www.tinyurl.com/GameRoomMedalChart