Play "Assault on the Control Room". It doesn't matter what difficulty setting or if you are playing 1 or 2 player mode. Get to "If I only had a super weapon". Rush right ahead and ignore the Jackals and the first Elite. Instead, kill the second one as he is somind over the hill. Then run to the next one who is coming around the banshee. If you kill them both, the two banshees will be yours for the taking. I would suggest using the Plasma Rifle for killing them, as it stuns. You can use the 2 banshees for a banshee fight with a friend, too. Anyways. Ignore the enemies and do not go to the end of the bridge. Instead, go to the top of the hill that leads to the Control Room. There will be no Hunters, or aliens on the way up the hill! There will be the enemies that come out of the big door, though, but this shave's precious time off the level.