Gears of War to feature full co-op play

In an interview on RewiredMind CliffyB reveals some information on Gears of War's co-op. The entire game will be playable in co-op, instead of a few levels added on just for the purpose. In splitscreen, system link, or over Xbox Live, someone can just drop in and play with you, and you can still unlock all the achievements or even play to the end with them (Will there be a way to stop people from joining and playing only the last few minutes of a level with their friends just so they can get an achievement?). If you decide you want to play with a buddy, just invite them and they will join as a spectator of the character they will take over - and when they are ready they just hit Start and take control.
[Via Evil Avatar]