This is a mod made by a Korean mapper. The read me is almost empty. It seems to be a remake of Half-Life! It starts with a tram ride, followed by collecting your hazard suit, then pushing the material into the test chamber and watch things go wrong.
It has perhaps the longest (and most dangerous) training mission I've seen :D. Must have been a beta version map that wasn't used and so instead used for "training". The mod itself is also very long. But while it has some good level design, in its first half... things start to change after you reach the pumping stations. From then on (including the surface levels) its pretty mediocre, random open couryards with some boxes fighting large groups of either headcrabs or grunts. It gets pretty hard…