I think there's a little more than just graphical detail lost in the PSP port. For one, the game really makes good use of the Wiimote interface, almost second to No More Heroes. Like for example, if you take notice of certain details by highlight them with the flashlight, Harry will comment on them, and similarly the game takes cues from those responses (commented and none commented), so there's a level of immersion you don't normally get from pressing buttons to "Check".I am playing the PSP ver. & Goodness Gracious it looks amazing for a PSP game !
Though the Wii ver. is even more amazing with its added visual oomph ! [real snow particles that collide ! ]. The atmosphere is brilliant.
Yeah, they did the particle effects really well for this game. Of course, no one will ever match Team Silent in the art department, but Climax has come very close to emulating it. And it's sad to hear that this might be the last game Akira Yamamoka composes for...