Achievement Tip // They've Always Been Faster
Clear the 2nd mission without setting foot in a drivable vehicle.
Do not enter the vehicle for the next portion of the level if you want to land the They've Always Been Faster Achievement. You can make it to the relay outpost on foot, you'll just have to fight off a few Elites and Jackals on the way.
Enter the driver's seat of the truck and WAIT FOR YOUR TEAMMATES to get in the passenger seat and bed of the truck. They will be able to fire at enemies as you pass them. You can also run down any enemies (and Moa birds) you encounter. With enough speed you can kill most enemies in one hit. Use the RIGHT TRIGGER for gas and use the ANALOG STICKS for braking/reversing and turning.
Drive down the road and zip past any enemies you encounter -- your squad mates will take care of them and you'll be out of range before they can fire back. Your ultimate goal is a circle of buildings just past the bridge over the river.
This circle of buildings is infested with Covenant forces. Here you must apply a technique which you will use often in the coming levels: Find some safe spot just outside the enemy's firing range and drive near the enemies to let your teammates fire at them, then drive away to recover your shields. If you have enough room you can just drive in a figure-8 pattern to avoid fire. Don't get too close though, since the Grunts and Elites might stick a Plasma Grenade to your ride.
Data Pad Any Difficulty
In the circle of buildings you pass through during the truck-driving portion of Mission 02 // Winter Contingency, look for an open door on the south side. Enter the door and you'll find a soldier slumped against the wall with a Data Pad beside him.
After clearing out the Covenant forces -- try to use grenades on the Elites if they take cover in the buildings -- return to your vehicle, wait for your squad mates and drive down the hill to the north.
You should see another group of Moa on the way down the path, so run them over if you still lack the requisite amount for the Achievement. Pass any enemies you encounter. At the bottom of the hill your peers will exit the vehicle as a Dropship lands nearby.
Take cover behind the cement structure and examine the spot on the ground marked "Ordinance." Pick up the M392 DMR Designated Marksman Rifle here and keep your Plasma Pistol hand if it still has a charge. The DMR is sure to become your best friend in the campaign. It's extremely powerful, has a useful zoom and is always a perfect primary weapon for fighting common Covenant forces like Elites, Jackals, grunts and Buggers.
From cover behind the stone walls in the west you'll have the high ground in this fight. Your first order of business is to take out all the Grunts. Pick them off with your DMR and duck back behind cover when your shield takes a pounding.
Achievement Tip // An Elegant Weapon...
Kill 10 enemies in a Firefight or Campaign session with the DMR.
The DMR is the scoped Designated Marksman Rifle that's common in the Campaign. Get 10 kills with it to get this Achievement. Easy!
After a wave of Grunts, another wave of Grunts and Elites shows up. Grab a Plasma Pistol and keep your DMR handy to take out the Elites. First, make sure ALL the Grunts are eliminated. Now, charge a Plasma Pistol shot and unleash it on a nearby Elite to drop its shields. Your team may pick it off, but fire a few DMR shots for good measure. Use this method to eliminate all three Elites.
After the area is cleared of Covenant, get on the transport that lands nearby and you'll be transported to a new area.
Immediately after disembarking the vehicle, toss a grenade into the clump of shielded Jackals below you. The Jackals with shields block nearly all fire if you try to shoot them from the front. However, you can target the small gap in their shield where their hand or claw or whatever grips the shield. Shoot this and they'll reel back, allowing you to shoot their head or chest quickly for a kill. You can also shoot them from the side or from behind to avoid the shield.