30th August 2010, 5:12 AM
Okay I found an answer to this. Apparently, for all the gun effects at least, the explanation is in the new "aiming system". The original aiming just moved the camera, but the new one actually animates Samus' gun moving around the screen. It seems the original "special effects" for the various beam weapons were actually all 2D overlays on the screen, and since those would look terrible any time the gun wasn't dead center, they just did the lazy thing and dummied out the visuals entirely rather than recode all the effects in 3D. This doesn't explain the changed water effects though.
"On two occasions, I have been asked [by members of Parliament], 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able to rightly apprehend the kind of confusion of ideas that could provoke such a question." ~ Charles Babbage (1791-1871)