Post your party members near where you entered, and circle around to the right to flank any unsuspecting enemies, finishing them off for good. They will likely stack up and be amongst the last enemies you kill, as standard Batarian soldiers fall much easier. The most worthy of these enemies are Batarian Commanders, who have resilient shields and lots of energy. The idea here is simple enough return fire on your foes to thin their ranks. Batarians galore occupy this room, mostly on the far side, behind some glass. This room is where you're going to be spending a majority of your time, and the amount of time you spend here will be greatly dependent on how quickly you go about your business.