I made it to 67% in practice and then I gave up and watched a video. The fact that this is a megacollab isn't inherently a bad thing, and I think there's maybe some sense in which it makes sense for a level that pays homage to the horror genre to have a wide variety of voices. However, the consequence is that the worst parts massively drag down the best ones. The construction zone part with all the tech slopes and stuff was by far my favorite both in terms of gameplay and visuals, and all I could think while playing it was "I wish this were its own separate level so I didn't also have to contend with the boring schlock around it".

Also, in one of the parts, the creator commits an unforgiveable level design sin: they make it so that doing any skips/doing the part in an unintended way causes an invisible trigger to just not give you the correct portal. It's especially egregious here because it isn't even immediately clear that you can't progress, the portal literally doesn't show up. It's bullshit and the hallmark of a lazy creator.