Black Mesa is a remake of the original Half Life in the (somewhat newer) Source engine. And it's on Steam now. And it costs money.
Selling a game for money isn't surprising, and in this case you are getting most of the single player campaign via Early Access in a form that isn't a broken mess. So that's a good thing. But Black Mesa was always envisaged as a free remake, not a paid for full game.
In this case, it's a remake of a game from 17 years ago, using technology which first appeared all the way back in 2004. There's nothing about Black Mesa which could be described as cutting-edge, but it does represent the better part of a decade of work by an international team of modders and enthusiasts. Here's the trailer.
It certainly looks a lot better than Half Life, and that's just a glimpse at the 10 or so hours of single player content you can get right now on Steam Early Access. For €19.99 you get about 95 percent of the campaign (before the alien Xen levels basically) and six new multiplayer maps. That's a lot more than most early access titles and could be a great way for new players to experience one of Valve's best games.
It's not finished yet though. The Black Mesa team will be working with the community to not only polish the existing levels but also create their own spin on the disappointing final chapters of the original game. It's not yet known how much they'll differ but any new take on Xen would be most appreciated.
A full retail release of the game will follow once that material is finished - at some unknown future time - for €24.99. So get most of a game cheaper right now if you're interested in replaying a prettier version of Half Life.
Black Mesa is available on Steam now for €19.99.