Earthbound reference...
	Easy "Haymaker" achievement...
	Path to War: Achievements...
	Purchase cheats...
	Various Achievements...
	Various completion bonuses...

Near the start of the game, Kara gives you a "Franklin Amulet" which is supposed to protect against lightning.

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.

Complete the following achievements to unlock Xbox Live Gamerscore points.

Achievement	How to unlock
A Taste of their Own (20 points)	Eliminate 10 enemies using one of their own turrets.
Air Superiority (30 points)	Clear a safe path to the Terraformer for Hale.
Armored Cavalry (20 points)	Rescue the pinned-down Red Faction soldiers.
Bird of Prey (20 points)	Allow no Red Faction to survive your attacks on their mountain base.
Full of Malice (30 points)	Kill Mallus.
Nuke It from Orbit (30 points)	Wipe out the Cultist military camp.
Stick Around (20 points)	Get 20 kills with the Sharpshooter.
Swath of Destruction (30 points)	Reunite Sgt. Winters with the Red Faction.
Triple Threat (30 points)	End the three-way battle between yourself, the aliens, and the Cultists.
Wrecking Ball (20 points)	Get 20 kills with the Shard Cannon.

These cheats can be purchased for the indicated price. Nice!

Unlimited Ammo:
Arc Welder: 5,000.
Assault Rifle: 5,000.
Banshees: 5,000.
Charge Launcher: 5,000.
Nano Rifle: 5,000.
Pistols: 5,000.
Plasma Beam/Mr. Toots: 5,000.
Plasma Cannon: 5,000.
Pulse Grenade: 5,000.
Rail Driver: 5,000.
Rocket Launcher: 5,000.
Shotgun: 5,000.
Singularity Cannon: 5,000.
XNG-5000: 5,000.

Visual Modes
Night Vision Mode: 8,000.
Sketch Mode: 10,000.

Weapon Unlocks:
Convergence Laser: 8,000.
L.E.O. Machine Gun: 6,000.
L.E.O. Rocket launcher: 8,000.
Lava Barge Turret: 6,000.
Napalm Laser: 10,000.

The rest
Instant Nano Forge: 10,000.
Super Melee: 8,000.

To unlock Xbox Live Gamerscore points, complete the following Achievements.

Achievement	How to unlock
All For One, One For All ( 25 points )	Finish a 4 player Infestation game beyond wave 9 without anyone bleeding out.
Back At Ya! ( 20 points )	Make an enemy kill themselves while shooting at your Shell.
Boom Goes The Dynamite ( 10 points )	Kill 2 other enemies with a single exploding Berserker.
Breathe Easy ( 30 points )	Put an end to the threat, once and for all.
Bug Hunt ( 20 points )	Finish at least one wave on each map in Infestation.
Catch! ( 30 points )	Use the Magnet Gun to fling debris BACK at a Tentacle.
Cheater! ( 20 points )	Buy a Cheat.
Chronicler ( 25 points )	Listen to 40 Audio Logs.
Commando ( 50 points )	Finish waves 1 through 20 on any map in Infestation.
Crack Shot ( 10 points )	Kill a Wraith before it re-stealths.
Crusader ( 15 points )	Kill 175 enemies while in the L.E.O. exoskeleton.
Exterminator ( 15 points )	Destroy 100 Pods while piloting the Mantis.
Family Business ( 20 points )	Defeat the Mantis.
Field Surgeon ( 15 points )	Perform Revival 25 times in Infestation.
Haymaker ( 10 points )	Kill 5 enemies in one shot with Impact.
Hit 'N Run ( 15 points )	Kill an enemy by ramming them with the Inferno GX.
Hold Still ( 10 points )	Kill 6 enemies in one use of Shockwave.
Honorary Mason ( 75 points )	Finish waves 1 through 30 on any map in Infestation.
I Need A Nap ( 75 points )	Finish the Single Player game on Insane Difficulty.
I'm All You've Got ( 15 points )	Defend the Red Faction.
In. The. Face! ( 25 points )	Kill one of each enemy type with the Maul.
It's All In The Wrist ( 15 points )	Send an enemy at least 30 meters with Impact.
Knock, Knock ( 15 points )	Open up the secret entrance.
Liftoff ( 10 points )	Send an enemy at least 50 meters with the Magnet Gun.
Lock And Load ( 20 points )	Keep Berserk active for at least 21 seconds in one use.
Losses ( 15 points )	Make it through to the lair.
Martian Can Opener ( 40 points )	Buy every Upgrade.
Martian Drive-By ( 15 points )	Kill 100 enemies while in the Marauder Scout Walker.
Martian Matchmaker ( 10 points )	Fire an enemy into another enemy with the Magnet Gun.
Money Well Spent ( 15 points )	Buy out any one Upgrade ring.
Must Go Faster ( 15 points )	Travel to the Marauder homelands.
Nanergy! ( 30 points )	Gather 25,000 total salvage.
Old Friends, Older Enemies ( 15 points )	Safely escort Winters through the depths.
One Big, Ugly Motha... ( 20 points )	Defeat the source of it all.
Ooooh Yeah! ( 10 points )	Kill 5 enemies with one L.E.O. shoulder bash.
Plan B ( 15 points )	Find out how to reach the lair.
Salvager ( 20 points )	Find 200 piles of salvage.
Secrets Long Buried ( 10 points )	Remove the Seal.
Soldier ( 25 points )	Finish waves 1 through 10 on any map in Infestation.
Survival Of The Fittest ( 15 points )	Make it to the surface.
That Coulda Gone Better ( 30 points )	Finish the Single Player game on Hard Difficulty.
Things Fall Apart ( 20 points )	Destroy the Water Filtration Plant.
Unto The Breach ( 15 points )	Gain entry into the Terraformer.
Vanguard ( 15 points )	Escort the convoy.
We're Not Alone ( 10 points )	Make it back to civilization.
Weather The Storm ( 15 points )	Destroy the Jamming Devices.
What Is Best In Life? ( 15 points )	Perform melee finishers on 25 Creepers ( single player only).
Zero G War ( 20 points )	Kill 50 Shockwaved enemies before they hit the ground.

Successfully complete the game to unlock Mr. Toots, the "Cheats" menu, and New Game+ mode!