Half-Life 2

For this one you’ll need to find the hidden singing Vortigaunt in a cave on the chapter “Water Hazard.” Right after you destroy the hunter-chopper you’ll need to open the gate and go straight ahead to a couple of large drain pipes. You’ll need to park the airboat under the left one and climb up into the pipe. Jump run all the way through and to the left as it is radioactive in here and you’ll take damage going through there. You’ll come up to a camp with the Vortigaunt and activate the achievement. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to play through the entire chapter of “We Don't Go To Ravenholm” while only using the Gravity Gun. If you accidentally switch to a gun or something as long as you do not fire it, throw anything, or switch your crowbar you’ll still be able to get the achievement. Taking a circular blade with you through the chapter will help a lot with this. I also made a video guide going over all of the achievements in the game here.

For this achievement you'll need to find all 45 of the lambda caches throughout the game. I have a video guide going over all of these here.

For this achievement you’ll need to gain command of a squad of rebels during the uprising. The first time you’ll get a squad of rebels is at the beginning of the chapter “Anticitizen One.” A group will run up to you automatically unlocking the achievement. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to cross the antlion beach without touching the sand in the chapter “Sandtraps.” For this one you’ll basically just need to go slowly and take any large flat items with you to use as platforms and bridges while going through. I also made a video guide going here going over this and all of the other achievements in the game.

For this one you’ll need to kill 5 enemies using manhacks. There are also multiple chapters that you can do this on. You’ll need to grab the manhacks with your gravity gun and either run up to the combine soldiers or just shoot it at them to kill them. I also made a video guide going over this as well as all other achievements in the game here.

For this one you’ll need to kill an enemy with a toilet. There are multiple chapters where this could be done, but you basically just need to pick one up with a gravity gun and shoot it at an enemy to kill them. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to kill all of the snipers in City 17. There are 5 snipers you’ll have to kill that are sitting in blacked out windows on the chapter “Follow Freeman.” You can use rockets or grenades to get this done. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to use DOG’s ball to make a basket in Eli’s scrapyard. Once you play catch with DOG you can start trying to throw the ball into the basket ball hoop. It took me a few reloads to get this before the combine came so it may take a few tries. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to disintegrate 15 soldiers by throwing them into a combine ball field. Once on the chapter “Our Benefactors” your gravity gun will be upgraded and you can start picking up enemies and putting them into these large energy ball fields. Do this as much as you can and you’ll get this achievement pretty quickly. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to pin a soldier to the billboard in the chapter “Highway 17.” Before coming up to the area with the combine at the billboard there is a hill with a crossbow on top. You can grab it here and then shoot the soldier to pin them to the billboard. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to break the mini-teleporter in Kleiner’s lab on the chapter “A Red Letter Day.” If you just keep teleporting the cactus back and forth eventually it will break and the achievement will pop. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to kill 3 enemies using the crane on chapter “Highway 17.” Once you use the crane and the three combine soldiers run out, just pick things up and drop it on top of them until they are all dead. I also made a video guide going over all of the achievements in the game here.

This one is for destroying the citadel’s reactor core and finishing the game. At the end of the chapter “Dark Energy" you’ll have to fight two gunships with energy balls and then shoot the energy balls into the large reactor until it is destroyed. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to destroy six gunships during your play-through. As long as you destroy most that you come across you’ll eventually get this. Any time you see a large ammo box of rockets chances are there will be some gunships around for you to destroy. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to shut down the suppression device on the chapter “Follow Freeman.” After meeting up with Barney you’ll get to the nexus building which you’ll then have to disable multiple energy ball reactors. Once that is done Barney will finish disabling the suppression device and the achievement will unlock. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to survive the generator plaza standoff in the chapter “Anticitizen One.” Later on in this chapter Alyx will join you again and start disabling a generator. During this time multiple waves of Combine soldiers will attack, and once Alyx finishes you’ll get the achievement. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to get through the toxic tunnel in City 17. This will happen later on in the chapter “Anticitizen One” while leading a squad of rebels. You’ll come to a locked door which only you can unlock. You’ll go through that radioactive tunnel and then unlock the door from the other side, activating the achievement. I also made a video guide going over all of the achievements in the game here.

This achievement is for surviving the second turret standoff in Nova Prospekt. During the chapter “Entanglement” you’ll have to defend Alyx and the teleporter with a few turrets at your disposal. Once you get through the fight and teleport away you’ll get the achievement. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to pick up the HEV suit charger faceplate in Eli’s scrapyard. Once on the chapter “Black Mesa East” you’ll go into Eli’s scrapyard and receive the gravity gun. Up on the area above there you’ll need to climb up and grab the faceplate with the gravity gun. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to kill 50 enemies by controlling antlions. After killing the first large antlion you’ll be given the ability to use pheropods to control antlions. You’ll then go up to and into Nova Prospekt and can sit back, use the pods, and kill the soldiers using these. Doing that you’ll eventually get the achievement. I also made a video guide going over all of the achievements in the game here.

For this achievement you'll need to hit the trash can cop with the can. At the beginning of the game on chapter “Point Insertion” when the cop knocks over a soda can and tells you to pick it up you can grab it and throw it at him to unlock this achievement. I also made a video guide going over all of the achievements in the game here.

While on the chapter "Highway 17" you'll come up to a small base called Little Odessa. For this achievement you'll need to defend this base from the gunship attack. Once it has been destroyed you'll receive the achievement. I also made a video guide going over all of the achievements in the game here.

While on the chapter "We Don't Go To Ravenholm" Father Grigori will meet up with you and you’ll start going through a cemetery filled with zombies and headcrabs. Once you escort him safely through you’ll receive this achievement. I also made a video guide going over all of the achievements in the game here.

For this one you’ll need to kill five barnacles with one barrel. You can do this on the chapter “Route Kanal” pretty easily. Once you get to this slime tunnel you’ll see a large amount of barnacles. Grab an exploding barrel and throw it down. Shoot it once it gets close to them to blow it up and you’ll get the achievement. I also made a video guide going over all of the achievements in the game here.

For this achievement you’ll need to get the gravity gun in the chapter “Black Mesa East.” After arriving here Alyx will take you out into Eli’s junk yard and give you the gravity gun which will unlock the achievement. I also made a video guide going over all of the achievements in the game here.

Once you have the turret attached to your airboat on the chapter "Water Hazard," you'll then be able to defeat the hunter-chopper later on that level. Once it has been destroyed you'll get this achievement. I also made a video guide going over all of the achievements in the game here.

For this one you'll need to put the can in trash. At the beginning of the game on the chapter "Point Insertion" a cop will knock a can over and tell you to pick it up. If you do as he says the achievement will pop up. I also made a video guide going over all of the achievements in the game here.

While going through the chapter "Water Hazard" you’ll come across a resistance camp. A vortigaunt will mod the airboat with a turret which will unlock this achievement. I also made a video guide going over all of the achievements in the game here.

A little bit later into the chapter “Route Kanal” you’ll run into a resistance fighter that has gotten an airboat ready for you. Once you get in it and take off you’ll get the achievement. I also made a video guide going over all of the achievements in the game here.