Even though Square-Enix seem to have royally sucked at PC compatibility in the past, I think this game would've performed well as a PC title for one simple reason: It's a shooting game.
I've not played the PS2 version because I royally suck at analog aiming (can't move my thumbs lightly or subtly enough) although I did notice when watching someone else play that there's an auto-aim which is very forgiving and you just need to get your target near the middle of the screen, as opposed to mouse control where, since controls are always so much more precise, you never need it.
Anyone else think so, then?
LATE EDIT: By wacky coincidence, I've just been lent this game, and discovered that it's keyboard and mouse compatible... somehow. Too bad I ain't got USB keyboard and mouse, eh?