black mesa
I've been playing Black Mesa, and I've gotten up to Xen, and I have to say that they've done an outstanding job.
They've managed to make it feel alien, while also expanding on the mechanics of the core game.
It's beautiful, and (most importantly to me) it actually makes the story behind xen more clear.
The scientists at black mesa were already sending survey teams to explore xen, and while that's said in some side dialogue in half life 1, you never really saw it.
(cont)
black mesa
Black Mesa (the game) adds scanning equipment, and tents, and various pieces of quick-set-up infrastructure and machinery, to make it clear just how much they were messing around in the border world.
black mesa
(One of the expansions to the original game, Blue Shift, also included some great xen sections which showed off this kind of stuff, and it's something that the original game was very sorely missing.)
