How many of us managed to get the 10,000 kills in the original, and perhaps 100,000 kills in Gears of War 2?
I'm sure the other titles must have had similar achievements, but I'm not familiar with them so I won't include them in the question. Feel free to comment if so, though!
https://www.trueachievements.com/game/Gears-of-War/achievements?gamerid=575
I managed the 10,000 kills in the original (I seem to recall it took somewhere around 17,000 kills to unlock) - I didn't get around to finishing 100,000 in the sequel.