It's testament to the quality of Black Mesa, a free Half-Life 2 mod, that we're able to review it like a normal game. This isn't just Half-Life with a texture upgrade; it's a lovingly crafted remix that remains faithful to the source material, but also makes its own mark on Valve's breakthrough FPS. As well as a stunning visual overhaul, the AI is smarter, maps are bigger, and new physics puzzles have been added to take advantage of the Source engine.
It all starts with a tram ride. Gordon Freeman arrives at the Black Mesa Research Facility at 8:48am - the exact time the mod was launched - and rides the transit system to a top secret complex buried deep beneath the New Mexico desert. In 1998 this was revolutionary; a story told without cutscenes, viewed entirely through the eyes of the player. In Black Mesa, it's still an incredibly effective, sophisticated way of telling a story and creating a sense of place.
We move slowly past bubbling pools of toxic waste, now given a sickly glow by Source's bloom lighting. A frustrated guard pounds on a malfunctioning security door. A mysterious figure in a blue suit silently observes you from an adjacent tram. Black Mesa's production values are seriously impressive. If you'd told us Valve developed it, we wouldn't have blinked an eye. The facility feels bigger and more alive, and the ominous sense that everything's about to go disastrously wrong is even more palpable. The Black Mesa team, which consists of around 40 volunteers, knew they had to get this iconic sequence right, and they've nailed it.
It's a shame about the loading. One of Source's biggest flaws is map size, which even Portal 2 suffered from. Turning a blind corner, or activating an elevator, will often freeze the game and load up the next chunk of level. It's a fault of the engine, not the modders, but it really disrupts the flow of the game; especially in certain sections that require you to backtrack. The abundance of first-person platforming is another unfortunate remnant of the past, and not being able to see your legs when you're skipping between tiny, fast-moving platforms in the Lambda Core will have all but the most patient gamers slamming their mouse on the desk in frustration.
An experiment goes awry and opens a portal to another universe, flooding Black Mesa with bizarre aliens and forcing Freeman to fight his way to the surface. This is the event that sets the Half-Life series' story in motion. But you never really know what's going on: the story is relayed by survivors who are just as lost and confused as you, or messages overheard on military radios. This feeling of isolation and disconnection only adds to the chaos erupting around you. The Black Mesa team have added some new dialogue, but the script is largely unchanged. The voice acting is a mixed bag. The scientist and security guards sound almost identical to their 1998 counterparts, but the HECU Marines aren't as menacing as they used to be.
They're still a blast to fight, though. The sheer variety of enemies in Black Mesa shames the hordes of identikit soldiers that have become the norm in modern first-person shooters. Bullsquids launch arcs of poisonous venom; Vortigaunts zap you from afar with bolts of green lightning; Houndeyes charge you in packs and blind you with bursts of telekinetic energy; Grunts unleash swarms of angry alien hornets. The Marines work in tight groups, flanking you and flushing you out of cover with grenades. The formidable Black Ops assassins sneak up on you from behind and leap around the level to confuse you. There's no regenerating health, and you'll spend much of the game limping around with only a few HP: as it should be.