One of the great retro FPSes, Shadow Warrior is somewhat similar in gameplay to Duke Nukem 3D. The game is definitely quite difficult, but the introduction of quicksaving and quickloading eases off the difficulty for newer players. Since much of the game's humor comes from he hilariously stereotypical protagonist Liu Wang, some players may find it racist, but it's all just in good fun. The game looks good for its time, and the sound assets are great.
Gameplay wise, the game plays great. The player can fight enemies with his fists, a katana, dual-weilding uzis, a rocket launcher with optional heat seeking missiles and even a nuke, a heart that creates a clone of Liu Wang, and more. The stage design is usually a major strength in old FPSes, and Shadow Warrior is no exception. The huge, expansive stages are fun to explore and packed with secrets. Enemy variation is not the best, but there's definitely enough to keep the player entertained.
The port remains faithful to the original, but one of the new editions is a multiplayer mode. It works well, but I rarely use it. One of the multiplayer's greatest strengths is the ability to design stages and share them with full Steam Workshop Support.
It may not be as well known as Duke Nukem 3D or Doom, but it's definitely just as good. From veterans to new players alike, Shadow Warrior Classic Redux is a classic that's definitely still worth the price today.