| Achievement | How to unlock
|
|---|
| "You. Black Mesa" | Reunite old foes.
|
| A Place in the Record Books | Heroically listen to the entirety of the Following Portents commentary.
|
| Big Mama | Survive the gonarch.
|
| Literacy 101 | Finish Following Portents.
|
| Moore Than Enough | Finish The Charnel House.
|
| Reckless Abandon | Disembark from the church.
|
| So There's Eleven | Find the kidnapped children.
|
| Speed Run | "Beat" Half-Life in record time.
|
| The Last Order | Discover Operation Exodus.
|
| VACANCIES | Check-in at the Franklin Motel.
|
| Vort Rider | Escape the antlion horde... on horseback!
|