What is the name of this PS2 game with the orange morphing character?

There’s a game I had years ago for the PS2 where you control an orange and black humanoid creature that traversed a mainly purple environment.
The creature had 3 forms: A humanoid form, a sort of shadowy stealth form and a bulky gun form.

I only remembered it recently and I can’t remember the name, which is frustrating me! Please help my frustrated nerdiness.