Black Mesa Beta is complete and available on Steam
Black Mesa has been created for about 15 years and finally saw the light of day in the complete version.
The most notable release notes point is "Added Interloper C, Interloper C1, Interloper D, Nihilath boss battle, Endgame".
The game is a collective work of artists from the Crowbar Collective studio, who have put together a Half-Life campaign (together with the areas of Xen and Gonarch Lair).
Many probably remember that the title was released in parts before. The creators admit that there may be bugs in the game (e.g. old save files will cause problems ) and warn that this is more a beta version than the final work. They ask for your understanding and promise to monitor any problem reports.
If you want to visit the world known from HL1 before the release of Half-Life: Alyx, Black Mesa can be purchased on Steam. Running the game is not so easy, so the developers left a short instruction.