Co-op mode and 2v2 would be great.

Co-op mode with someone with you in the iron nest. Lots of chaos would ensue. Imagine being attacked and your buddy is running around and yelling what is going on.

2 v 2 would be you have a bunch of targets and then you can't engage each other. Imagine you are 2 different countries facing a similar insurgency or rebellion. At the end you must find and destroy each other. Thoughts?