Shadow Warrior was an ambitious game for its time, containing many features not seen until later first-person shooter games, such as drivable vehicles, climbable ladders, and multiple firing modes for various weapons. The game was rebuilt in 2014 with OS X support and published by 3D Realms.
The full game (including two expansion packs) is being offered on Steam as a free download, but picking it up from GOG also gets gamers the original soundtrack in MP3 and FLAC format as an additional freebie. The remastered "Redux" version of the game is also available on Steam for $0.99 as part of a 2017 Summer Sale.
Shadow Warrior Classic has the following minimum requirements: OS X 10.6.8 or later, an Intel Core Duo 2GHz processor, 1GB RAM, 64MB of video memory, and 1GB of hard disk space.