Someone went ahead and rebuilt Kojima's PT in Half-Life: Alyx, and I'm immediately nope-ing away from that. Not only because it sounds utterly claustrophobic and dreadful, but also because I'd need to stumble across a small fortune to afford Half-Life: Alyx, a compatible VR headset, and a stronger PC.
Anyway, from the looks of it, AmbientDruth's creation is pretty spot-on, though not exactly the same as Kojima's horror masterpiece. The hallways are a little wider, the lighting a little brighter, and in general the house just looks cleaner. I'd imagine that could mitigate some of the terror of playing PT, but for something built inside of an entirely different game, it's damn impressive.
While it's still a work-in-progress, there's already a lot here to mimic the PT experience broadly. The hallways form a loop, so every time you think you're done you emerge right at the beginning again. You'll also experience Lisa's haunting voice, the creeping presence of the radio broadcast, and the red-lit corridor ending.
AmbientDruth says they're planning on refining the textures to look more like the real thing, and plans are in the works for a laundry list of additions to more closely replicate Kojima's PT. It goes without saying, but this is still Half-Life: Alyx you're playing, so don't expect a 1:1 experience. Though, you can donate to the creator's efforts here if you want to see things move along a little quicker.
We might never see PT evolve into a full game, but Kojima says he has plans for a "revolutionary" new horror game he hopes will make you crap your pants.