Achieved | Achievement | % of players | Unlock date |
|---|---|---|---|
 | Brownian Motion Pass the toilet paper to the Scientist in need. | 84.96% | |
 | Convection Refinement Ruin the microwave casserole. | 72.82% | |
 | Gray Matter Propulsion Headshot 20 Enemies with the .357 Magnum. | 59.68% | |
 | Prophylactic Suggested Get overtaken by a Headcrab's ample anterior. | 50.41% | 30/09/2017, 15:33:19 |
 | Caffeine Extraction Perform surgical caffeine extraction from 20 vending machines. | 38.73% | |
 | Permeable Infrastructure Use the alternate path in Office Complex. | 30.97% | |
 | Centripetal Attraction Kill 20 Enemies with the Hivehand. | 29.87% | |
 | Proverbial Tinkerer Interfere with the alarm and laptop in Anomalous Materials. | 26.33% | |
 | Inflammatory Actions Kill a Headcrab using fire. | 25.68% | |
 | Quantum Capacitance Overcharge it anyway. | 21.83% | |
 | Dead Reckoning Kill an Assassin with the .357 Magnum. | 20.8% | |
 | Universal Gravitation Get killed by your own Snarks. | 14.54% | |
 | Resonance Procrastinator Refuse to insert the specimen into the Anti-Mass Spectrometer. | 13.98% | |
 | Calculated Trajectory Kill 10 airborne Headcrabs using the Shotgun. | 13.05% | |
 | Remote Detonation Kill a Barnacle with a Satchel. | 12.31% | |
 | Digital Wizardry Kill 10 enemies with a reprogrammed Sentry. | 11.62% | |
 | Mega Hertz Kill 5 Enemies with one Grenade. | 10.96% | |
 | Nuclear Fishin' Kill an Ichthyosaur with either the Tau or Gluon. | 9.97% | |
 | Hyper Saturation Conundrum Drown in Lambda Core's coolant. | 9.38% | |
 | Ethically Questionable Conduct all of the questionable research experiments. | 9.06% | |
 | Futile Resistance Kill 10 Enemies with Snarks. | 8% | |
 | Premature Expulsion Use an entire clip of Gluon ammo in one continuous shot. | 7.97% | |
 | Unified Coupling Theorum Help the Barnacle and Headcrab find true love. | 6.22% | |
 | Kinetic Repulsion Kill a Marine with their own Grenade. | 5.73% | |
 | Rare Specimen Send the Hidden Hat to Xen. | 3.35% | |
 | Rather an Anticlimax Decline G-Man’s offer of employment. | 0% | |
 | Our Brains And Your Brawn Assemble all the possible Scientists and Guards at the end of Office Complex. | 0% | |
 | Prolific Popper Kill all Protozoans in the Borderworld. | 0% | |
 | The Rarest Specimen Carry the Hidden Hat to Endgame. | 0% | |
 | Late for Work Defeat Nihilanth in under 4 minutes. | 0% | |
 | Specimen GG Take out all three Healing Crystals in Nihilanth’s Chamber at the same time. | 0% | |
 | Stealth Technology Escape the Hangar in Surface Tension without alerting the Soldiers. | 0% | |
 | The Plan Use Cyanogen to kill Gonarch. | 0% | |
 | Unquestionably Ethical Don't use the Cyanogen and let the Gonarch live. | 0% | |
 | Well-Done Cook a Grenade for too long. | 0% | |
 | Following the Rules Use the welcome mat. | 0% | |
 | Pepperoni Precipitation View the *other* secret ending. | 0% | |
 | Post-Mortem Interval Find each member of the missing research teams. | 0% | |
 | Gonad Glider Get whacked into oblivion in the ledge fight. | 0% | |
 | Doctor’s Signature Deliver the finishing blow to Gonarch with your Crowbar. | 0% | |
 | Anti-Matter Over Mind Kill a Controller without killing any of its mind-controlled Vortigaunt slaves. | 0% | |
 | Black Mesa Decathlon Winner Escape the Gargantua’s Lair without taking any damage from Gargantuas. | 0% | |
 | Laser Immunization Complete Interloper without taking any laser damage. | 0% | |
 | Less Than Desirable Consequences Die in the AMS Beam before starting the experiment. | 0% | |
 | Limitless Potential Accept G-Man’s offer of employment. | 0% | |
 | One Step Ahead Kill 10 Enemies with Tripmines. | 0% | |
 | Orbital Trajectory Skip the opening Xen island with a secret jump. | 0% | |
 | Contest Propellant Find the snack supply canister. | 0% | |
 | PhD in Pacifism Don't kill any Vortigaunts in the Borderworld. | 0% | |
 | xen when Wait too long to jump into the Lambda Teleporter. | 0% |