Downloads are available from the mod's ModDB page or right here as a 7z or zip archive. The 7z is about 40mb smaller, but it requires the 7zip archive utility available for free from To install either, extract the gamma_energy folder to your sourcemods folder, which is typically located in C:\Program Files\steam\steamapps on Windows. Mac users can also use the mod, but the instructions may be a bit more convoluted. I'll post details and instructions when I've tried them myself.