| Achievement | How to unlock
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| Brownian Motion | Pass the toilet paper to the scientist in need.
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| Caffeine Extraction | Perform surgical caffeine extraction from 20 machines.
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| Calculated Trajectory | Kill 10 Airborne Headcrabs using the Shotgun.
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| Centripetal Attraction | Kill 20 enemies with the Hivehand.
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| Convection Refinement | Ruin the microwave casserole.
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| Dead Reckoning | Kill an Assassin with the .357 Magnum.
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| Digital Wizardry | Kill 10 enemies with a reprogrammed Sentry.
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| Ethically Questionable | Conduct all of the questionable research experiments.
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| Futile Resistance | Kill 10 enemies with Snarks.
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| Gray Matter Propulsion | Headshot 20 enemies with the .357 magnum.
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| Hyper Saturation Conundrum | Drown in Lambda Core's coolant.
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| Inflammatory Actions | Kill a Headcrab using fire.
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| Kinetic Repulsion | Kill a Marine with their own grenade.
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| Mega Hertz | Kill 5 enemies with one grenade.
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| Nuclear Fishin' | Kill an Icthyosaur with either the Tau or Gluon.
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| Permeable Infrastructure | Use the alternate path in Office Complex.
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| Premature Expulsion | Use an entire clip of Gluon ammo in one continuous shot.
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| Prophylactic Suggested | Get overtaken by a Headcrab's ample anterior.
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| Proverbial Tinkerer | Interfere with the alarm and laptop in Anomalous Materials.
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| Quantum Capacitance | Overcharge it anyway.
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| Rare Specimen | Send the Hidden Hat to Xen.
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| Remote Detonation | Kill a Barnacle with a Satchel.
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| Resonance Procrastinator | Refuse to insert the specimen into the Anti-Mass Spectrometer.
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| Unified Coupling Theorum | Help the Barnacle and Headcrab find true love.
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| Universal Gravitation | Get killed by your own Snarks.
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