It's good!

Honestly, it might be on par with Opposing Force, in my opinion. The new setting gives everything a new, refreshing change in atmosphere. The tweaks made to the weapons feel really good. I thought every weapon had a nice punch, and pulling off headshots was so satisfying thanks to the new gib effects. This mod is a good showcase of GoldSrc as well, with the game using different kinds of scenery and weather effects in certain stages and set pieces. I really like when good Half-Life mods like this get released out of nowhere on Steam, so I would definitely recommend playing this if you already like Half-Life (which you probably do). It's free, and it's densely packed with content even with the short 6-hour runtime.