Aliens Colonial Marines

There are 3 challenge categories, with the 2nd being the easiest to complete for this achievement because there are only 13 to do. These are the campaign challenges which can be seen in Service Records-> Challenges. For most of these challenges you can abuse the reload last checkpoint function.

Solid Legs: Complete a campaign mission on any difficulty
-Easy enough. Just like it says.

Splattered: Gib 5 enemies in a single campaign mission
-Use your secondary fire grenade launchers and splatter some xenos. The default ones on the Pulse Rifle and Pump Shotgun work great.

Better Than Harsh Language: Kill 5 enemies with melee in a single campaign mission
-Melee 5 enemies to death until you get this.

Nice Groupings: Kill 2 enemies with a single shot from the Pump Shotgun
-When you've got 2 enemies close to each other and pretty much right in front of you, kill them both with one shot. Might require some luck.

Tactical Supremacy: Kill 6 enemies with Tactical weapons in a campaign mission
-This was very confusing when I did it as I thought it meant the tactical shotgun but what it refers to are your firebombs, grenades, and claymores. Hold Y and push your left stick to the left to equip different ones and get 6 kills in one mission. Use left on the D-Pad to bring them out and RT to throw/place.

Double Tap: Kill 2 enemies that are stunned in a campaign mission
-Use the Tactical Shotguns secondary fire to stun and then finish them off.

Bug Hunter: Kill 5 facehuggers
-These are the annoying little scorpion-like things that jump on your face. They appear as early as Mission 2 but there are also a ton at the start of the second to last mission after you pick up the flamethrower.

Sawbones: Remove a total of 20 limbs from xenomorphs
-This can take time if you're just firing at their center of mass. It's best to just aim for their legs and you will get this eventually. Rifles and shotguns are both fine.

Iron Fist: Kill 10 enemies with melee in a single campaign mission without dying
-This can be tricky if there are human enemies around firing at you and also with your partners shooting everything. It's best done on recruit on the first mission after rescuing Keyes. Keyes will cut open a door and you will be on your way to retrieve a Flight Rec. There are some easy xenos here to melee and just reload the checkpoint until you have 10, as long as you don't die.

Superior Firepower: Kill 2 enemies with the Smart Gun, Flamethrower or RPG in a campaign mission
-Smart gun is in Mission 4 but the fastest way to get this is the start of the second to last mission. Just run to the door and cut it open. You'll find a flamethrower soon on your left and keep going past the cocooned scientists to start burning away. Also the area with a lot of facehuggers.

Inside Out: Kill 5 enemies with explosives in a campaign mission
-These can be with grenades or launchers. Just blow up 5.

Battle Hardened: Complete a campaign mission on Hardened or higher difficulty

Ultimate Badass: Complete a campaign mission on Ultimate Badass
-For the last 2 challenges just play the last level as it's easy and relatively quick.

One good spot for these and also the Marine challenges can be the first enemies you encounter in Mission 3. There are a bunch of human enemies and most of them are just running to the exits. You can reload to your heart's content. This is obviously not for xeno specific challenges.

Hope this guide helped for this particular achievement.

There are 3 challenge categories, with the 2nd being the easiest to complete for this achievement because there are only 13 to do. These are the campaign challenges which can be seen in Service Records-> Challenges. For most of these challenges you can abuse the reload last checkpoint function.

Solid Legs: Complete a campaign mission on any difficulty
-Easy enough. Just like it says.

Splattered: Gib 5 enemies in a single campaign mission
-Use your secondary fire grenade launchers and splatter some xenos. The default ones on the Pulse Rifle and Pump Shotgun work great.

Better Than Harsh Language: Kill 5 enemies with melee in a single campaign mission
-Melee 5 enemies to death until you get this.

Nice Groupings: Kill 2 enemies with a single shot from the Pump Shotgun
-When you've got 2 enemies close to each other and pretty much right in front of you, kill them both with one shot. Might require some luck.

Tactical Supremacy: Kill 6 enemies with Tactical weapons in a campaign mission
-This was very confusing when I did it as I thought it meant the tactical shotgun but what it refers to are your firebombs, grenades, and claymores. Hold Y and push your left stick to the left to equip different ones and get 6 kills in one mission. Use left on the D-Pad to bring them out and RT to throw/place.

Double Tap: Kill 2 enemies that are stunned in a campaign mission
-Use the Tactical Shotguns secondary fire to stun and then finish them off.

Bug Hunter: Kill 5 facehuggers
-These are the annoying little scorpion-like things that jump on your face. They appear as early as Mission 2 but there are also a ton at the start of the second to last mission after you pick up the flamethrower.

Sawbones: Remove a total of 20 limbs from xenomorphs
-This can take time if you're just firing at their center of mass. It's best to just aim for their legs and you will get this eventually. Rifles and shotguns are both fine.

Iron Fist: Kill 10 enemies with melee in a single campaign mission without dying
-This can be tricky if there are human enemies around firing at you and also with your partners shooting everything. It's best done on recruit on the first mission after rescuing Keyes. Keyes will cut open a door and you will be on your way to retrieve a Flight Rec. There are some easy xenos here to melee and just reload the checkpoint until you have 10, as long as you don't die.

Superior Firepower: Kill 2 enemies with the Smart Gun, Flamethrower or RPG in a campaign mission
-Smart gun is in Mission 4 but the fastest way to get this is the start of the second to last mission. Just run to the door and cut it open. You'll find a flamethrower soon on your left and keep going past the cocooned scientists to start burning away. Also the area with a lot of facehuggers.

Inside Out: Kill 5 enemies with explosives in a campaign mission
-These can be with grenades or launchers. Just blow up 5.

Battle Hardened: Complete a campaign mission on Hardened or higher difficulty

Ultimate Badass: Complete a campaign mission on Ultimate Badass
-For the last 2 challenges just play the last level as it's easy and relatively quick.

One good spot for these and also the Marine challenges can be the first enemies you encounter in Mission 3. There are a bunch of human enemies and most of them are just running to the exits. You can reload to your heart's content. This is obviously not for xeno specific challenges.

Hope this guide helped for this particular achievement.

There are 3 categories of challenges you can complet, and you only need to complete one of them for this achievement. Category 2 is by far the easiest to complete as it has only 13 challenges and most of them are quite simple. I have listed each challenge along with the best way I have found to complete it. There are many “spots” that are good for complete various challenges. If you have found a spot that works well for a particular challenge, please list it in the comments and I will add it to the solution. Also note that for many of the challenges, you can abuse the “Reload Checkpoint” feature. Needless to say, all of these challenges will be easier to do on Recruit difficulty.

There is one particular “spot” that we will be using a lot for these challenges, and that is at the very beginning of Mission 2 – Battle For Sulaco. You will start out on the bridge of the ship. As soon as you gain control, you’ll go to the exit door at the back left (facing rear of bridge) of the bridge. Two soldiers will burst through this door momentarily. This is the spot I’m talking about, so for the rest of this solution I’ll just call it the Challenge Spot.


Category 2 Challenges

Solid Legs – Complete a campaign mission on any difficulty. It’s just that easy. Complete any campaign mission on any difficulty.

Splattered – Gib 5 enemies in a single campaign mission. To gib an enemy, you need to blow them to pieces. Easiest to do this with grenades or an underslung grenade launcher. Can be humans or xenos. Any mission will do really. Not cumulative, so you have to do this within one mission.

Better Than Harsh Language – Kill five enemies with melee in a single campaign mission. This one can be frustrating and it is much, much easier to do on human enemies as xeno executions do not count. Go to the Challenge Spot. When the two soldiers break in, shoot one of them. When the other one crouches behind the crate on the right, quickly sprint forward and melee him to death. Now reload your checkpoint, rinse and repeat four more times. Beware, if you die your counter resets.

Nice Grouping – Kill 2 enemies with a single shot from the pump shotgun. Easiest on human enemies. Go to the Challenge Spot and equip the pump shotgun. Unequip the barrel choke attachment if you have it on so you get a wide spread, and equip expanding shot if you have it unlocked. Get to the left of the door before the guys break in. Many times they will both head for the crate on the right to try and take cover. When they are both side-by-side, unloose on them. May take a few tries. Took me around 5 attempts.

Tactical Supremacy – Kill 6 enemies with Tactical weapons in a campaign mission. This means grenades/claymores. Hold down Y and push left on the weapon radial. These are the tactical weapons. Just kill 6 enemies within a single mission. Easy-peasey. Any mission will do.

Double Tap – Kill 2 enemies that are stunned in a campaign mission. Equip the tactical shotgun and make sure the secondary fire is arc rounds. Use the arc round to stun an enemy with electricity and then kill him while he is stunned. Do this twice within a single mission.

Bug Hunter – Kill 5 Facehuggers. I used Mission 2. After leaving the bridge, you will go through several rooms and hallways. There are 5 or 6 facehuggers here. Use a shotgun and kill them. This is cumulative so you don’t need to do it in the same mission, but if you don’t get 5 the first time through just reload your checkpoint.

Sawbones – Remove a total of 20 limbs from xenomorphs. Load up Mission 4 – No Hope In Hadley’s. Do the first part of the mission with the shotgun of your choice and aim for the legs. Once you get the Smart Gun, head down to the tunnels and it will do a wonderful job of dismembering xenos. If you don’t get 20 by the end of the tunnel section, just reload you checkpoint. This is cumulative, so you don’t need to do it in one mission.

Iron Fist – Kill 10 enemies with melee in a single campaign mission without dying. This one can be frustrating and it is much, much easier to do on human enemies as xeno executions do not count. Go to the Challenge Spot. When the two soldiers break in, shoot one of them. When the other one crouches behind the crate on the right, quickly sprint forward and melee him to death. Now reload your checkpoint, rinse and repeat nine more times. You can try to melee both enemies, but beware, if you die your counter resets. This is not cumulative and must be done within a single mission.

Superior Firepower – Kill 2 enemies with the Smart Gun, Flamethrower, or RPG in a campaign mission. Just as easy as it sounds. Easiest to do on Mission 4 – No Hope In Hadley’s after you get the Smart Gun and go down in the tunnels.

Inside Out – Kill 5 enemies with explosives in a campaign mission. Pretty easy and any mission will do. Use grenades or an underslung grenade launcher to kill 5 enemies within the same campaign mission. This is not cumulative.

Battle Hardened – Complete a campaign mission on Hardened or higher difficulty. Not that hard. Complete any campaign mission on Hardened or Ultimate Badass difficulty. I used Mission 1 - Distress.

Ultimate Badass – Complete a campaign mission on Ultimate Badass. Still not that hard. Complete any campaign mission on Ultimate Badass difficulty. I used Mission 1 - Distress.