There's too many glitches when playing the PS1 version on a PS2. Like for instance even on easy the Catch Venom level is hard as heck because you stay in the building where the cutscene is instead of going onto the building where Venom is. Also on normal and hard difficultys you get stuck on the tunnel crawl level cause there's no way to crawl up the tunnel before the water rises up. So get this version.
"There's a difference you know between not liking one's brother and not caring when some dumb Irish flatfoot drops him out of a window." Simon Gruber