Full list of all 99 The Orange Box achievements worth 1,000 gamerscore. It takes around 80-100 hours to unlock all of the achievements on Xbox 360.
Knock down a turret with another turret.
Help Alyx snipe 30 enemies in Episode One.
Use the cars to squash 15 antlions in Episode One.
Find the HEV Suit Charger faceplate in Eli's scrapyard.
Kill 3 enemies using the crane.
Send the garden gnome into space.
Kill a Hunter with its own flechettes.
Kill an Elite Soldier with his own energy ball.
Find and break every web cache in Episode Two.
Don't let any citizens die when escorting them to the escape train.
Kill five enemies with a Manhack.
Get five revenge kills.
Win Well in 5 minutes or less.
Successfully defend Dustbowl without giving up a capture.
Use DOG's ball to make a basket in Eli's scrapyard.
Discover the hidden singing vortigaunt cave in chapter Water Hazard.
Hit the trashcan cop with the can.
Get five kills in a row without dying.
Run over 20 enemies with the car in Episode Two.
Find every radar cache in chapter Under The Radar.
Kill a Combine soldier with his own grenade.
Destroy the Citadel's reactor core.
Disintegrate 15 soldiers by throwing them into a Combine ball field.
Survive the rooftop strider battle in the ruins of City 17.
Kill five enemies with the same energy ball.
Destroy six gunships in Half-Life 2.
Shut down the supression device by disabling its generators.
Survive the generator plaza standoff in chapter Anticitizen One.
Get through the toxic tunnel under City 17 in Half-Life 2.
Gain command of a squad of rebels in the uprising.
Survive the second turret standoff in Nova Prospekt.
Use the antlions to kill 50 enemies.
Pin a soldier to the billboard in chapter Highway 17.
Defend Little Odessa from the gunship attack.
Escort Gregori safely through the church cemetery.
Kill 30 enemies with thrown physics objects.
Get the Gravity Gun in Black Mesa East.
Destroy the hunter-chopper in Half-Life 2.
Get the airboat's mounted gun.
Get the airboat.
Kill five barnacles with one barrel.
Complete Portal.
Get the crowbar.
Escape the apartment block raid.
Put the can in the trash.
Save the missile silo from the Combine offensive.
Secure the launch doors on missile silo 2.
Make the correct party escort submission position decision.
Survive the ambush at White Forest Inn.
Unlock the rocket launcher lambda cache in chapter Under The Radar.
Destroy the Combine cannon in the junkyard.
Survive the Hunter ambush with Alyx.
Defeat both antlion guards outside the White Forest.
Help Griggs and Sheckley hold off the antlion invasion inside the mine shaft.
Kill an enemy by planting a hopper mine.
Kill an acid antlion worker.
Escape City 17 with Alyx.
Destroy the gunship in the hospital attic.
Survive long enough to get on the parking garage elevator.
Steal a Zombine's grenade.
Contain the Citadel core.
Do whatever it takes to survive.
Acquire the fully powered Aperture Science Handheld Portal Device.
Make it to the bottom of the Citadel's main elevator shaft in one piece.
Use flares to light 15 zombies on fire.
Break the mini-teleporter in Kleiner's lab.
Play through Ravenholm using only the Gravity Gun.
Cross the antlion beach in chapter Sandtraps without touching the sand.
Kill an enemy with a toilet.
Kill all of the snipers in City 17.
Find all lambda caches in Half-Life 2.
Contain the Citadel core without killing any stalkers.
Beat Episode One firing exactly one bullet. Grenade, crowbar, rocket, and Gravgun kills are okay!
Squish every antlion grub in Episode Two.
Defeat the chopper in Episode Two without any misses.
Beat DOG in a race to the White Forest base.
Save all buildings outside the missile silo from destruction.
Fall 30,000 feet.
Jump 300 feet.
Beat two Portal advanced maps.
Beat four Portal advanced maps.
Beat all six Portal advanced maps.
Earn bronze medals on all Portal challenges.
Earn silver medals on all Portal challenges.
Earn gold medals on all Portal challenges.
Accumulate 10 turret kills with a single turret.
Trick an opposing medic into healing you.
Play in a game with seven or more players from your friends list.
Win 20 games.
Accumulate 1000 total kills.
Win 2Fort with a shutout.
Win Hydro without giving up a capture.
Successfully defend Gravel Pit without giving up a capture.
Play a complete round with every class.
Play a complete game on every map.
Accumulate 25000 heal points as a Medic.
Set five enemies on fire in 30 seconds.
Get 25 headshots as a Sniper.
Detach security cameras from the walls.