One morning in the New Mexico desert, a 27-year-old theoretical physicist arrives late. The "Half-Life" series is truly a long and unfortunate day at work, and "Black Mesa" follows Gordon Freeman's disastrous morning. Black Mesa is a completely fan-made but Valve-approved game that allows you to relive Gordon Freeman's harrowing morning.

The structure of Black Mesa is faithful to Half-Life. You take the tram to work, watch in horror as the Resonant Cascade floods the facility with aliens, dodge headcrabs in office buildings, clash with HECU marines, deal with giant tentacles in blast pits, fight on surface battlefields, navigate radioactive Lambda Core, and finally visit Xen. But everything is bigger, more detailed, and more dramatic, breathing new life into the Black Mesa incident with production values that approach those of Half-Life 2.

See the video above for a comparison of Half-Life's Xen and the remake.

Several levels have also been remixed, and puzzles and set pieces have been redesigned, in some cases completely new. So even those who are familiar with "Half-Life" will be in for a surprise. Purists, however, may question developer Crowbar Collective's design and aesthetic choices; Black Mesa is not a 1:1 remake and will not feel as authentic as revisiting the original. However, it is a fresh, modern, and lovingly crafted version of a landmark moment in PC gaming.

Half-Life is still great today, but as the years have passed relentlessly, it feels increasingly staid and dated. But Black Mesa, built on the foundation of Half-Life 2, borrows from its weaponry and chaotic physics simulation to create a more dynamic and engaging first-person shooter. And thanks to an abundance of movable, breakable objects and devious traps that frequently set off explosive chain reactions, the stricken research facility has never felt so reactive, unpredictable, or dangerous.

But let's talk about Xen, because this is where Black Mesa really shines. In the original Half-Life, Freeman's arrival in Xen was something of a letdown for most players. While not as bad as people remember, this alien world of floating platforms, strange alien plants, and filthy textures was the low point of the game, with frustrating low-gravity platforming maneuvers and tedious boss fights with giant ballsacks. But after years of development and several delays, "Black Mesa" did the impossible and made Xen one of the best parts of the game.

The new Xen looks stunning and feels truly strange and otherworldly, like this in-between place in the universe. Shortly after teleporting in, Freeman finds himself staring at a landscape of strange floating creatures and swirling, vibrant nebulae. Comparing both versions of "Zen" side by side, it is almost comical how much progress has been made. Places that were once lackluster and bleak now glow alive with color and detail, and the contrast between the relatively mundane computer, concrete, and vending machine establishments adds to the impact.

The new Zen levels loosely follow the original game in terms of theme and structure, but also represent a radical departure. Platforms are more fun and dramatic, and there is more to discover in terms of world building and environmental storytelling. Some locations have been completely transformed. In the Interloper section, Freeman encounters the enslaved Vortigaunts in a factory-like cloning facility. In Black Mesa, however, this section is replaced by a larger, much more evocative new location that really highlights the true misery of the Vorts' tragic enslavement.

The fight against the Gonarch is also much more exciting, and the animation and visuals are truly incredible. Nihilance will have to see for himself, but I will say that the new version is an improvement over the previous big floating baby. Maze-like level design and somewhat unnecessary puzzle solving notwithstanding, "Zen" is a triumph of confident, dazzling art direction and an ending to Freeman's first adventure that doesn't feel significantly inferior to his earlier work.

It's amazing that something as elaborate and well-made as "Black Mesa" is essentially a fan project. And it is doubly amazing that Valve not only made it, but allowed it to be sold on Steam as well. This is a professionally made game, and arguably the best way to experience the events of the Black Mesa Incident on a modern gaming PC, and while some may say that the best version of Half-Life will always be the original version, this one effectively uses the basic Half-Life 2 system It is a stunning re-imagining. Watching the Black Mesa facility shatter and fight its way through is exactly as thrilling as it was in 1998, and the story's ending is "Burn," not "Gahn."