31 Dec 2014 31 Dec 2014
I gained my 150-500 played games in about 5 minutes.
Completed Halo 2 in coop, my profile was the secondary signed in.
Went into Campaign - Halo 2 - scrolled trough missions - Pressed B to back out - back into Halo 2 and just rinse and repeat until i got my 500. Got no idea what triggered this and it did not work for my gf.
Feel free to try it out