Click on the PRO banner in the main menu OR launch DLC "SOK PRO Upgrade"
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.
Complete the game.
Complete Level 1
Complete Level 10
Complete Level 100
Complete Level 11
Complete Level 12
Complete Level 13
Complete Level 14
Complete Level 15
Complete Level 16
Complete Level 17
Complete Level 18
Complete Level 19
Complete Level 2
Complete Level 20
Complete Level 21
Complete Level 22
Complete Level 23
Complete Level 24
Complete Level 25
Complete Level 26
Complete Level 27
Complete Level 28
Complete Level 29
Complete Level 3
Complete Level 30
Complete Level 31
Complete Level 32
Complete Level 33
Complete Level 34
Complete Level 35
Complete Level 36
Complete Level 37
Complete Level 38
Complete Level 39
Complete Level 4
Complete Level 40
Complete Level 41
Complete Level 42
Complete Level 43
Complete Level 44
Complete Level 45
Complete Level 46
Complete Level 47
Complete Level 48
Complete Level 49
Complete Level 5
Complete Level 50
Complete Level 51
Complete Level 52
Complete Level 53
Complete Level 54
Complete Level 55
Complete Level 56
Complete Level 57
Complete Level 58
Complete Level 59
Complete Level 6
Complete Level 60
Complete Level 61
Complete Level 62
Complete Level 63
Complete Level 64
Complete Level 65
Complete Level 66
Complete Level 67
Complete Level 68
Complete Level 69
Complete Level 7
Complete Level 70
Complete Level 71
Complete Level 72
Complete Level 73
Complete Level 74
Complete Level 75
Complete Level 76
Complete Level 77
Complete Level 78
Complete Level 79
Complete Level 8
Complete Level 80
Complete Level 81
Complete Level 82
Complete Level 83
Complete Level 84
Complete Level 85
Complete Level 86
Complete Level 87
Complete Level 88
Complete Level 89
Complete Level 9
Complete Level 90
Complete Level 91
Complete Level 92
Complete Level 93
Complete Level 94
Complete Level 95
Complete Level 96
Complete Level 97
Complete Level 98
Complete Level 99
Start the game for the first time.
