I just cleared all the levels and challenges with a LV25 Commando and LV5 assassin(there's a challenge that forces you to use an assassin.). I used the OICW and Socom(all SMGs and Machine-Pistols are trash), ammo mastery(i wanted bullet feeder but forgot to switch to it.) and Tear Gas. main campaign was pretty easy (except for One Final Effort, but that was also quite easy.) Earlier challenges were pretty easy (especially man with the golden gun). Later challenges weren't too hard either(except Knife to A Gunfight and Self Experiments) Meet your makers was also pretty easy and I beat it on my first or second try, though I'm pretty pissed Justin and Mike were level 60 with some crazy-ass loadouts, though it's their game, so it's understandable.
Just 100%ed both human and alien campaigns. For Terminator, I used a blunderbuss(bolt trigger, heated barrel and memory foam) for homing and looper. You want to hit as many crotch/buttshots as possible for score bonuses since you need a lot of bonuses for your 3 star. I generally just wait for my allies to lower the T-14's health, before 1 shotting him with the blunderblunderbuss. If you don't have any living allies, take potshots at him until his health lowers, preferably with a sniper.
This game was stolen. It was uploaded by 2 uncredited people who weren't louissi with no explanation whatsoever and nickheadproductions has a bunch of other stolen games on their profile. Flag it.