This is a PS1 game. I have confirmed that it boots on a PS2. The case has significant scratches (see image 1). It's a dark 3D battle action game. You can choose characters, each with their own unique combos, which I remember being fun. I think there was also a mode where you could play as creatures after clearing the game... I haven't heard much about remakes or ports, so please try playing it with the original PS1 game.