Black Mesa achievements

27.42%

Mega Hertz

Kill 5 enemies with one grenade.

28.33%

Quantum Capacitance

Overcharge it anyway.

29.78%

Proverbial Tinkerer

Interfere with the alarm and laptop in Anomalous Materials.

32.09%

Centripetal Attraction

Kill 20 enemies with the Hivehand.

32.55%

Dead Reckoning

Kill an Assassin with the .357 Magnum.

33.17%

Permeable Infrastructure

Use the alternate path in Office Complex.

35.32%

Caffeine Extraction

Perform surgical caffeine extraction from 20 machines.

35.57%

Inflammatory Actions

Kill a Headcrab using fire.

37.59%

Premature Expulsion

Use an entire clip of Gluon ammo in one continuous shot.

46.90%

Prophylactic Suggested

Get overtaken by a Headcrab's ample anterior.

53.02%

Gray Matter Propulsion

Headshot 20 enemies with the .357 magnum.

68.44%

Convection Refinement

Ruin the microwave casserole.