A really solid shooter for its time that deserves to be praised as a pioneer of the FPS genre. The controls are hard to get used to at first but it is so worth hanging around to get used to them because they have really fun and diverse level designs that wouldn't be found in regular FPS'.
The game really shines in its multiplayer however, being the most entertaining part of it where everyone struggles to find and kill one another, and has a lot of replayability in the vast game modes. Really worth trying even for the sake of the legacy of the genre.