- Basic Science
Earn bronze medals on all Portal challenges.
- Rocket Science
Earn silver medals on all Portal challenges.
- Aperture Science
Earn gold medals on all Portal challenges.
05 December 2011 - 5 guides
- Camera Shy
Detach security cameras from the walls.
07 November 2011 - 2 guides
- Long Jump
Jump 300 feet.
07 November 2011 - 6 guides
- Lambda Locator
Find all lambda caches in Half-Life 2.
07 November 2011 - 3 guides
- Barnacle Bowling
Kill five barnacles with one barrel.
- Puttin' On a Clinic
Defeat the chopper in Episode Two without any misses.
04 November 2011 - 3 guides
- Get Some Grub
Squish every antlion grub in Episode Two.
04 November 2011 - 3 guides
- Terminal Velocity
Fall 30,000 feet.
08 June 2009 - 5 guides
- Vanilla Crazy Cake
Beat all six Portal advanced maps.
08 June 2009 - 3 guides
- Fruitcake
Beat four Portal advanced maps.
08 June 2009 - 3 guides
- Cupcake
Beat two Portal advanced maps.
08 June 2009 - 3 guides
- Heartbreaker
Complete Portal.
- Partygoer
Make the correct party escort submission position decision.
05 June 2009 - 3 guides
- Fratricide
Do whatever it takes to survive.
05 June 2009 - 2 guides
- Friendly Fire
Knock down a turret with another turret.
05 June 2009 - 3 guides
- Lab Rat
Acquire the fully powered Aperture Science Handheld Portal Device.
- Submissive
Put the can in the trash.
05 June 2009 - 3 guides
- Vorticough
Discover the hidden singing vortigaunt cave in chapter Water Hazard.
05 June 2009 - 2 guides
- Defense of the Armament
Save the missile silo from the Combine offensive.
- Neighborhood Watch
Save all buildings outside the missile silo from destruction.
05 June 2009 - 7 guides
- Secondary Silo Secured
Secure the launch doors on missile silo 2.
- Little Rocket Man
Send the garden gnome into space.
05 June 2009 - 5 guides
- Pedal to the Metal
Beat DOG in a race to the White Forest base.
05 June 2009 - 2 guides
- Cache Checker
Find every radar cache in chapter Under The Radar.
05 June 2009 - 2 guides
- Quiet Mountain Getaway
Survive the ambush at White Forest Inn.
- Gordon Propelled Rocket
Unlock the rocket launcher lambda cache in chapter Under The Radar.
05 June 2009 - 2 guides
- Hit and Run
Run over 20 enemies with the car in Episode Two.
- Gunishment!
Destroy the Combine cannon in the junkyard.
- Payback
Kill a Hunter with its own flechettes.
04 June 2009 - 2 guides
- Meet the Hunters
Survive the Hunter ambush with Alyx.
- Twofer
Defeat both antlion guards outside the White Forest.
04 June 2009 - 2 guides
- Pinata Party
Find and break every web cache in Episode Two.
04 June 2009 - 3 guides
- Into the Breach
Help Griggs and Sheckley hold off the antlion invasion inside the mine shaft.
04 June 2009 - 2 guides
- Acid Reflex
Kill an acid antlion worker.
- The One Free Bullet
Beat Episode One firing exactly one bullet. Grenade, crowbar, rocket, and Gravgun kills are okay!
03 June 2009 - 5 guides
- Escape From City 17
Escape City 17 with Alyx.
03 June 2009 - 2 guides
- Citizen Escort
Don't let any citizens die when escorting them to the escape train.
03 June 2009 - 3 guides
- Attica!
Destroy the gunship in the hospital attic.
- Live Bait
Help Alyx snipe 30 enemies in Episode One.
03 June 2009 - 2 guides
- Elevator Action
Survive long enough to get on the parking garage elevator.
- Zombie-que
Use flares to light 15 zombies on fire.
03 June 2009 - 2 guides
- Car Crusher
Use the cars to squash 15 antlions in Episode One.
03 June 2009 - 3 guides
- Grave Robber
Steal a Zombine's grenade.
03 June 2009 - 3 guides
- Containment
Contain the Citadel core.
- Pacifist
Contain the Citadel core without killing any stalkers.
03 June 2009 - 2 guides
- Hardcore
Accumulate 1000 total kills.
02 June 2009 - 12 guides
- Watch Your Head!
Make it to the bottom of the Citadel's main elevator shaft in one piece.
02 June 2009 - 2 guides
- Turret
Accumulate 10 turret kills with a single turret.
02 June 2009 - 6 guides
- Singularity Collapse
Destroy the Citadel's reactor core.
- World Traveler
Play a complete game on every map.
01 June 2009 - 5 guides
- Head of the Class
Play a complete round with every class.
01 June 2009 - 4 guides
- Impenetrable Defense
Successfully defend Dustbowl without giving up a capture.
01 June 2009 - 3 guides
- Lightning Offense
Win Well in 5 minutes or less.
01 June 2009 - 3 guides
- Impossible Defense
Successfully defend Gravel Pit without giving up a capture.
01 June 2009 - 4 guides
- Atomizer
Disintegrate 15 soldiers by throwing them into a Combine ball field.
01 June 2009 - 3 guides
- Giant Killer
Survive the rooftop strider battle in the ruins of City 17.
- Relentless Offense
Win Hydro without giving up a capture.
01 June 2009 - 3 guides
- Conservationist
Kill five enemies with the same energy ball.
31 May 2009 - 7 guides
- Fight the Power
Shut down the supression device by disabling its generators.
- Counter-Sniper
Kill all of the snipers in City 17.
31 May 2009 - 3 guides
- Think Fast!
Kill an Elite Soldier with his own energy ball.
31 May 2009 - 3 guides
- Plaza Defender
Survive the generator plaza standoff in chapter Anticitizen One.
31 May 2009 - 2 guides
- "Radiation Levels Detected"
Get through the toxic tunnel under City 17 in Half-Life 2.
31 May 2009 - 2 guides
- Deadly Harvest
Kill an enemy by planting a hopper mine.
31 May 2009 - 2 guides
- Follow Freeman
Gain command of a squad of rebels in the uprising.
- What cat?
Break the mini-teleporter in Kleiner's lab.
31 May 2009 - 2 guides
- Warden Freeman
Survive the second turret standoff in Nova Prospekt.
31 May 2009 - 2 guides
- Flushed
Kill an enemy with a toilet.
31 May 2009 - 5 guides
- One Man Army
Destroy six gunships in Half-Life 2.
31 May 2009 - 2 guides
- Bug Hunt
Use the antlions to kill 50 enemies.
- Hack Attack!
Kill five enemies with a Manhack.
31 May 2009 - 4 guides
- Keep Off the Sand!
Cross the antlion beach in chapter Sandtraps without touching the sand.
31 May 2009 - 7 guides
- Targetted Advertising
Pin a soldier to the billboard in chapter Highway 17.
31 May 2009 - 2 guides
- OSHA Violation
Kill 3 enemies using the crane.
31 May 2009 - 2 guides
- Where Cubbage Fears to Tread
Defend Little Odessa from the gunship attack.
31 May 2009 - 2 guides
- Hot PotatOwned
Kill a Combine soldier with his own grenade.
31 May 2009 - 2 guides
- Zombie Chopper
Play through Ravenholm using only the Gravity Gun.
31 May 2009 - 5 guides
- Flamethrower
Set five enemies on fire in 30 seconds.
30 May 2009 - 8 guides
- Hallowed Ground
Escort Gregori safely through the church cemetery.
30 May 2009 - 3 guides
- Bone Breaker
Kill 30 enemies with thrown physics objects.
30 May 2009 - 2 guides
- Blast from the Past
Find the HEV Suit Charger faceplate in Eli's scrapyard.
30 May 2009 - 2 guides
- Two Points
Use DOG's ball to make a basket in Eli's scrapyard.
30 May 2009 - 3 guides
- Zero-Point Energy
Get the Gravity Gun in Black Mesa East.
- Revenge!
Destroy the hunter-chopper in Half-Life 2.
- Heavy Weapons
Get the airboat's mounted gun.
- Anchor's Aweigh!
Get the airboat.
- Grey Matter
Get 25 headshots as a Sniper.
29 May 2009 - 5 guides
- Dynasty
Win 20 games.
- Trusty Hardware
Get the crowbar.
- Malcontent
Escape the apartment block raid.
- Defiant
Hit the trashcan cop with the can.
29 May 2009 - 4 guides
- Team Doctor
Accumulate 25000 heal points as a Medic.
29 May 2009 - 12 guides
- Nemesis
Get five revenge kills.
29 May 2009 - 5 guides
- With Friends Like these...
Play in a game with seven or more players from your friends list.
29 May 2009 - 7 guides
- Hard to Kill
Get five kills in a row without dying.
29 May 2009 - 8 guides
- Powerhouse Offense
Win 2Fort with a shutout.
28 May 2009 - 3 guides
- Master of Disguise
Trick an opposing medic into healing you.
28 May 2009 - 6 guides