-mash b to while in the pod, then hold b while looking to the bottom right corner of the pod.
-run and do slide jumps to save time.
-throw 2 grenades once both the brutes have fallen from the phantom and use the SMG to kill the remaining grunts if any.
-throw another grenade at the grunts in the second fight area, hopefully you'll get plasma grenades to stick the brutes with, its really hard to get a sub 2 minute time because of this fight.
-run to the end, jump and smack your head on the ceiling in the hallways to save a lot of frames if you want to. be sure to hold b while going around the corner to the ending trigger so that you can end the level in the soonest possible frame.