I Believe I played this game on Playstation, but i was a child so it might have been xbox
I likely played this game some time between 1996 and 2003
RPG side scrolling real time game.
If i recall correctly 3d graphics
Camera view was primarily 2d sidescroller, but there may have been some areas whre the view was from behind the character.
The game as I remember it:
The game starts out with the player choosing to play as a the male or female protagonist. These characters have their own stories, which are interwoven. The male character has the ability to change shape into creatures he fights, and has limited slots with which to store these. (I somewhat remember if you died while in a form you lost it but not sure). The female had the ability to take powers from creatures she fought. I feel like I remember one of the enemies being a mushroom that jumped around a lot and was named "fun guy" and thinking that was funny. Combat was limited to 2d side scrolling in real time I am pretty sure.