I am a ps2 user, but bought this gem back when I had a ps1.  The game is exceptionally hard in one player mode as you have two charcters who you have to toggle between.  The game is both strategic and action oriented.  You can blast the enemy with your machine gunner or use the sniper to pick them off from a distance.  The game takes some effort to learn, but is well worth it.  One of the nice features on two player is that if your partner dies, the screen becomes full-screen for the remaining player.  GREAT GAME FOR ONE OR TWO PLAYERS!