Kill 10 airborne Headcrabs using the Shotgun.
Escape the Hangar in Surface Tension without alerting the Soldiers.
Kill 20 Enemies with the Hivehand.
Headshot 20 Enemies with the .357 Magnum.
Kill an Assassin with the .357 Magnum.
Use the alternate path in Office Complex.
Interfere with the alarm and laptop in Anomalous Materials.
Perform surgical caffeine extraction from 20 vending machines.
Get overtaken by a Headcrab's ample anterior.
Refuse to insert the specimen into the Anti-Mass Spectrometer.
Die in the AMS Beam before starting the experiment.
Pass the toilet paper to the Scientist in need.
Ruin the microwave casserole.
Kill 10 enemies with a reprogrammed Sentry.
Conduct all of the questionable research experiments.
Kill 10 Enemies with Snarks.
Drown in Lambda Core's coolant.
Kill a Headcrab using fire.
Kill a Marine with their own Grenade.
Kill 5 Enemies with one Grenade.
Kill an Ichthyosaur with either the Tau or Gluon.
Use an entire clip of Gluon ammo in one continuous shot.
Overcharge it anyway.
Send the Hidden Hat to Xen.
Kill a Barnacle with a Satchel.
Help the Barnacle and Headcrab find true love.
Get killed by your own Snarks.
Kill all Protozoans in the Borderworld.
Don't kill any Vortigaunts in the Borderworld.
Kill 10 Enemies with Tripmines.
Assemble all the possible Scientists and Guards at the end of Office Complex.
Skip the opening Xen island with a secret jump.
Deliver the finishing blow to Gonarch with your Crowbar.
Get whacked into oblivion in the ledge fight.
Find each member of the missing research teams.
Complete Interloper without taking any laser damage.
Escape the Gargantua’s Lair without taking any damage from Gargantuas.
Kill a Controller without killing any of its mind-controlled Vortigaunt slaves.
Take out all three Healing Crystals in Nihilanth’s Chamber at the same time.
Defeat Nihilanth in under 4 minutes.
Accept G-Man’s offer of employment.
Decline G-Man’s offer of employment.
Cook a Grenade for too long.
511
1363
