A contemporary of Half-Life 1 and the very first computer game to make use of the LithTech Engine, Shogo: M.A.D. distinguishes itself from other first-person shooters because of its anime-like style and its two-phase (human and mecha) dynamics.
The story is simple but convincing: in the future, several factions strugglie for the control of the mysterious Kato energy. The protagonist, who lost his brother and girlfriend in a mission that was supposed to end the war (and didn't) is sent to finish the job. However, things soon become very complicated, with many twists in the plot.
The man- and mecha-based phases are well characterized; the second one is especially well made, and it's fun to jump from roof to roof. The violence in the game is so high that it ends up being ludicrous; this, together with the rather high damage dealt by weapons (but it's Doom's fault to have spoiled players into thinking they can survive a direct hit from an RPG) can generate some frustration in the player at certain stages of the game, especially in the man-based phases. However, this is widely compensated by a strong sense of humour, which is especially evident in the dialogues. The multiplayer is also good, with maps dedicated to men and mechas.
The manga-style graphics can displease some eyes, especially for what regards the human figures. The physics is not as sophisticated as in recent games, but don't forget that 1: it's a 1998 game and 2: it's an anime ;)
Overall, though not a classic, Shogo: M.A.D. is a very entertaining piece of software and well worth its money.