The long-awaited and Valve sanctioned Half-Life 1 re-envisioning Black Mesa has been released on Steam Early Access for £14.99.
It's not quite finished, as I suppose the Early Access badge had you guess. Around 85 per cent of the single-player campaign is done, the final 15 per cent still needing "considerable time" - "putting a time estimate on it would be a total guess," the Black Mesa Steam page explains.
As it stands, Black Mesa offers a SP campaign with "over 10 hours" of play, plus multiplayer deathmatch and team deathmatch modes, on six "completely re-imagined" HL1 maps.
The full game will have a full campaign, pus the addition of the Xen chapters, as well as more multiplayer maps and more multiplayer modes.
Developer Crowbar explained that it opted for Early Access to both bring in the community for feedback as well as the resources needed to finish Black Mesa to the standard fans expect.
Black Mesa recreates Half-Life in the Source engine, but also adds new choreography, new voice acting, and a new soundtrack. It also supports Steam Workshop.
There are a couple of newer Black Mesa videos on the game's Steam page that I can't find on YouTube to embed. Sorry!