Gears of War 2

To get this achievement, you must complete the first 10 waves of horde on any difficulty. You do not need to do this on one sitting, and you do not need to do it all on one map.
You should not aim for this achievement as it will unlock on your way to one of:
Hoard the Horde
Trial by, and on, Fire
Skeletons in your Closet

I suggest if you are planning to go to level 50, then security is the best map as the bunker area surrounded by lasers is a very good defensive position.

I also suggest grabbing a friend to help you do this so that you have room for error.

Easy achievement, and fun.
Just make it to the 10th wave on horde. It can be any game map, multi-player,or just you alone. It tracks all the horde games you’ve played. So say you hop on solo and make it to the 4th wave, then some other day your on xboxlive and make it to the 5th wave, it will track that.

I got it the 1st time I played horde online on the 1st day map with a random group from xboxlive. I tried to stay up on the steps overlooking the center hole it was pretty fun.

A lot of the multiplayer achievements are hard to keep a track of. Here is a checklist that I put together to keep a tab of where I was in the achievements.

https://www.dropbox.com/s/etn3vy85lwax6z8/Gears%20of%20War%2...

Hope it helps.

It will stay up unless my bandwidth gets exceeded.