This achievement is unattainable on the Xbox. This achievement is also unattainable with the PC. When the game 1st came out, it was unattainable. They released patch 2, and it was attainable. Then they released patch 3 (current), and it is unattainable again.
Thus, to get it this is what you have to do. On PC, if you have been playing the game, you have to re-install the game. When you launch the game, you will be on patch 1. When you log into live, it will tell you that there is an update to the game (this way then you know for sure that you have an unpatched game). Decline, and then quit out. There are many places to get patch 2, this is where I went : http://universeatwar.filefront.com/file/Universe_at_War_Eart...
Run that file and your game will now have patch 2. When you re-load the game and 'sign in'. Decline the update. You will be signed in, but you will not be connected to live. You can then get this achievement.
To get the achievement, make a 8-player skirmish game. Pick Grand Canyon. Pick 2 Novus allies, medium difficulty (on hard, they kill the enemy to fast). Pick 5 more Novus easy opponents, but all on different teams. Pick Masari as your faction. You can either have your base surrounded by your two allies if you wish, but I actually found it better to be closer to the enemy. At the most you can put a turret or 2 next to your base to protect it.
Next you will need to research Dark Matter Suite 2 (middle one). You can build a few Matter Engines if you wish while waiting, but you should have enough money to research and build Altea. The reason you need more money is because it would be better to research up to suite 4 for more armor.
Along the way switch to Dark mode. You get extra shields. Altea has 2 powers. One is shield, and the other is Unmake. She moves slowly, so you have to move to the enemy base and
use her unmake power on the resource gathers
. You can also use them on Ohm robots. There are some material cashes around the map that have massive resources. What happens is that many resource gathers from all the opponents will eventually go there. On Grand Canyon, there is a military base, and there are many structures in the water. The trick is to be fast enough and try and unmake as many as possible before they start building tougher units. It takes about 1 minute for the power to regenerate. Unmaking structures should work, but takes to long. Also, your allies start to kill the enemies which becomes a bit of a pain.
The description says that it has to be during a skirmish game session. The 1st time I played, I did not get the achievement. I know I was close, but missed. I decided to try again, and within a couple of unmakes I got it. Thus there must be a continuous counter over several games which will help.
Some IMPORTANT notes.
1. You will get the achievement, but there will be no date stamp
2. DO NOT re-install your game if you are doing other achievements 1st. You will loose all progress in your campaign and apparently your online stats will also get reset. Thus consider doing this as the last achievement if you have been working on other achievements.
3. If you have access to another computer, then you could load the game on that, put patch 2 and then get this achievement. The only problem is that you will not be able to download your gamertag to a new computer without getting the update to the game. The easiest workaround would be to download Tinker (free), and then download your gamertag. That way it will be on your computer 1st, before playing this game. This way your on-line stats and campaign progress will not get reset. Just remember that you eventually have to log into live for your achievement to get recorded, so go back to tinker, and sign into live. Play on tinker for a few minutes to make sure that the information gets 'official'.
Hope this helps.
As others have mentioned, it seems that it does not work on resource gathers. I cannot for the life of me remember, so I stuck out that line above. I am glad the solution is still working for others. I will add the new link for patch 2 if it helps others.http://www.gamewatcher.com/downloads/universe-at-war-earth-a...