Heck, I fought every Geth Colossus and almost all Armatures on foot, just for kicks. All the challenge in the game came from chasing individual enemies around the map, wearing down their extraordinary health bars as my massively-overpowered weapons blasted them around the room. In the original mass Effect, Insanity difficulty was tiring more than it was difficult as a max level soldier with Colossus X heavy armor, my damage reduction and health regeneration maxed out, and the at-that-point-redundant Immunity ability at its third level, I was never in any danger of dying.
