Complete 20 levels
Complete 50 levels
Complete 100 levels
Earn 20 cubotroxes
Earn 50 cubotroxes
Earn 100 cubotroxes
Place 10 correct cubes consecutively
Place 20 correct cubes consecutively
Place 30 correct cubes consecutively
Place 4 correct cubes in 2 seconds
Score points 10 times consecutively with the maximum multiplier
Score points 100 times with the maximum multiplier
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.
Ruin the microwave casserole.
Kill an Assassin with the .357 Magnum.
Kill 10 enemies with a reprogrammed Sentry.
Conduct all of the questionable research experiments.
Kill 10 enemies with Snarks.
Headshot 20 enemies with the .357 magnum.
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 Icthyosaur with either the Tau or Gluon.
Use the alternate path in Office Complex.
Use an entire clip of Gluon ammo in one continuous shot.
Get overtaken by a Headcrab's ample anterior.
Interfere with the alarm and laptop in Anomalous Materials.
Overcharge it anyway.
Send the Hidden Hat to Xen.
Kill a Barnacle with a Satchel.
Refuse to insert the specimen into the Anti-Mass Spectrometer.
Help the Barnacle and Headcrab find true love.
Get killed by your own Snarks.
