I'm going in with Mordin and Grunt to take out the Geth Colossus without any ammo. I'm totally out. I can get to the corners in the far left or far right side of the screen, but the Geth soldiers keep coming and by the time I get the power cells I still don't have a whole lot of ammo and I'm invariably overtaken by the Geth soldiers. The sniper nook on the far right side is a great place, but once you get the power cells you can't jump back up there. I've died like 15 times on this one part. If I had enough ammo, or a character with Warp or Overload, it would be so much easier. Is there any way to abort the mission and go back in with the right characters and enough ammo, or is there a way for me to beat it as is?