Win in 3st level
Win in 2st level
Win in 1st level
Pass the toilet paper to the scientist in need.
Perform surgical caffeine extraction from 20 machines.
Kill 10 Airborne Headcrabs using the Shotgun.
Kill 20 enemies with the Hivehand.
Use an entire clip of Gluon ammo in one continuous shot.
Help the Barnacle and Headcrab find true love.
Kill an Assassin with the .357 Magnum.
Kill 10 enemies with a reprogrammed Sentry.
Conduct all of the questionable research experiments.
Ruin the microwave casserole.
Get killed by your own Snarks.
Headshot 20 enemies with the .357 magnum.
Drown in Lambda Core's coolant.
Kill a Barnacle with a Satchel.
Kill a Headcrab using fire.
Kill a Marine with their own grenade.
Kill 10 enemies with Snarks.
Kill 5 enemies with one grenade.
Kill an Icthyosaur with either the Tau or Gluon.
Use the alternate path in Office Complex.
Interfere with the alarm and laptop in Anomalous Materials.
Get overtaken by a Headcrab's ample anterior.
Overcharge it anyway.
Send the Hidden Hat to Xen.
Refuse to insert the specimen into the Anti-Mass Spectrometer.
