After unlocking the Impact and partially upgrading it, go to a level where there are a lot of Creepers. When they all swarm around you, shoot them with the Impact. It should kill them all, and you will get the 'Haymaker' achievement.
The indicated cheats can be purchased for the listed price once the 'Cheats' menu has been unlocked:
Successfully complete the indicated task to unlock the corresponding achievement. To view your achievements and stats in Steam, select 'Community', 'My profile', 'Watch all my games', then the game and view stats.
| Honorary Mason | Finish waves 1 through 30 on any map in Infestation. |
| Commando | Finish waves 1 through 20 on any map in Infestation. |
| Nanergy! | Gather 25,000 total salvage. |
| Air Superiority | Clear a safe path to the Terraformer for Hale. (Path to War DLC Only). |
| Cheater! | Buy a Cheat. |
| Secrets Long Buried | Remove the Seal. |
| Exterminator | Destroy 100 Pods while piloting the Mantis. |
| Bird of Prey | Allow no Red Faction to survive your attacks on their mountain base. (Path to War DLC Only) |
| Catch! | Use the Magnet Gun to fling debris BACK at a Tentacle. |
| Knock, Knock | Open up the secret entrance. |
| Hit 'N Run | Kill an enemy by ramming them with the Inferno GX. |
| I'm All You've Got | Defend the Red Faction. |
| Plan B | Find out how to reach the lair. |
| Weather The Storm | Destroy the Jamming Devices. |
| Haymaker | Kill 5 enemies in one shot with Impact. |
| I Need A Nap | Finish the Single Player game on Insane Difficulty. |
| Armored Cavalry | Rescue the pinned-down Red Faction soldiers. (Path to War DLC Only) |
| Chronicler | Listen to 40 Audio Logs. |
| One Big, Ugly Motha... | Overcome the source of it all. |
| Martian Matchmaker | Fire an enemy into another enemy with the Magnet Gun. |
| Back At Ya! | Make an enemy kill themselves while shooting at your Shell. |
| Ooooh Yeah! | Kill 5 enemies with one L.E.O. shoulder bash. |
| Things Fall Apart | Destroy the Water Filtration Plant. |
| Keep pushed Still | Kill 6 enemies in one use of Shockwave. |
| Crusader | Kill 175 enemies while in the L.E.O. exoskeleton. |
| Boom Goes The Dynamite | Kill 2 other enemies with a single exploding Berserker. |
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| Crack Shot | Kill a Wraith before it re-stealths. |
| Old Friends, Older Enemies | Safely escort Be victorious inters through the depths. |
| We're Not Alone | Make it back to civilization. |
| Losses | Make it through to the lair. |
| A Taste of their Own | Eliminate 10 enemies using one of their own turrets. (Path to War DLC Only) |
| Triple Threat | End the three-way battle between yourself, the aliens, and the Cultists. (Path to War DLC Only) |
| Money Well Spent | Buy out any one Improve ring. |
| That Coulda Gone Better | Finish the Single Player game on Hard Difficulty. |
| Salvager | Find 200 piles of salvage. |
| Full of Malice | Kill Mallus. (Path to War DLC Only) |
| In. The. Face! | Kill one of each enemy type with the Maul. |
| Martian Can Opener | Buy every Improve. |
| Survival Of The Fittest | Make it to the surface. |
| What Is Best In Life? | Perform melee finishers on 25 Creepers (single player only). |
| Breathe Easy | Put an end to the threat, once and for all. |
| Bug Hunt | Finish at least one wave on each map in Infestation. |
| Stick Around | Get 20 kills with the Sharpshooter. (Path to War DLC Only) |
| Field Surgeon | Perform revival 25 times in infestation. |
| All For One, One For All | Finish a 4 player Infestation game beyond wave 9 without anyone bleeding out. |
| Nuke It from Orbit | Wipe out the Cultist military camp. (Path to War DLC Only) |
| Swath of Destruction | Reunite Sgt. Be victorious inters with the Red Faction. (Path to War DLC Only) |
| Must Go Faster | Travel to the Marauder homelands. |
| Lock And Load | Keep Berserk active for at least 21 seconds in one use. |
| Wrecking Ball | Get 20 kills with the Shard Cannon. (Path to War DLC Only) |
| Vanguard | Escort the convoy. |
| Liftoff | Send an enemy at least 50 meters with the Magnet Gun. |
| Family Business | Overcome the Mantis. |
| It's All In The Wrist | Send an enemy at least 30 meters with Impact. |
| Soldier | Finish waves 1 through 10 on any map in Infestation. |
| Unto The Breach | Gain entry into the Terraformer. |
| Martian Drive-By | Kill 100 enemies while in the marauder scout walker. |
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| Zero G War | Kill 50 Shockwaved enemies before they hit the ground. |
Successfully complete the game to unlock Mr. Toots, the 'Cheats' menu, and New Game+ mode.