This is a rather short but good mod. It takes place in a chemical facility, an interesting environment for a mod. It’s very Black Mesa-esque in level design. Before you download this you should know that the combat is terrible. There are a whole bunch of zombies that you can easily kill with a crowbar a few Metrocops at the end easily taken out with the pistol. If I play it again I will play it on hard and I suggest you do so yourself. The puzzles are the important point of the mod. They’re all science based and there’s even a quiz on elements. It doesn’t really make sense that the people in this facility, with the threat of losing their lives just around the corner, stop and inform the new guy about science. I just laughed when I just turned the air back on and saved my and the other person’s life then talked to them and they said “AIR!”. It’s pretty silly. The puzzles are very interesting. The only problem apart from combat is that it’s really short. If they made an entire mod with this premise I would most likely love it. To people like me who are interested in science, play it. For people who are not I can’t really recommend it.