The closest thing yet to pen & paper Battletech for the PSOne.
Graphically it's hard on the eyes. Big, pixelated textures and a low-polycount amount to a certain degree of visual hellaciousness that can tax your interest right away. And sound for its part sooths the sizzling of one's rods and cones with responsive effects for things like missiles launching, machine guns firing and bare-fisted, battle-bot style bashing. Put it this way; if you could stand the over-world of Xenogears and still enjoy that game, you can probably see past the lackluster looks of FM 3 to appreciate the meat of the experience: turn-based mech combat.
For any given mission, you can control up to 4 player-characters which pilot their own unique mech. The tank-like machines themselves can be configured in a number of ways to suit a particular role--brawler, machine gunner, sniper, long-range support, and so on. Configurations effect things like movement range, firing-range and damage done to a particular target. You decide what to do with your available units, and when finished, the CPU takes its turn in handling your opposition. This repeats until some victory condition is met. It might sound like standard fare for turn-based strategy, but if you have a certain enthusiasm for the genre or games featuring giant robots that go boom, it hits the spot.
The story detracts the game with long-winded dialogue, forgettable characters and a pacing that can bore one to suicide. There's also a sort of internal Internet within the game that can be accessed between missions. It's purely optional and serves to expand upon the characters' development, which would matter if you could manage to give a damn.