game ran like shit on the PS2 and had shitty shit image quality, hardly a technical achievement unless you have Sfag goggles on Come now. Yes, it definitely didn't run well, but they were utilizing techniques the likes of which the PS2 had no business attempting. Its technology is more of a curiosity than anything else, I think.
I'm curious as to why you don't feel it is an impressive feat. The image quality was pretty good for a PS2 game, so really, it's only significant problem was its performance. A big deal, no doubt, but that shouldn't completely negate the rest of the feats either.
I mean, they managed to sneak in..
1) Not only camera motion blur but per object motion blur
2) Low precision HDR lighting (HDR lighting was extremely uncommon in 2005 and very demanding)
3) Full self-shadows (stencil shadow volumes were used similar to Doom 3)
4) "fur/grass shading" from a machine which had nothing resembling programmable shaders
5) Inverse kinematics for animation (proper collision and dynamic animation when interacting with different moving and stationary surfaces)
6) Volumetric particles (for clouds, fog, and other such things)
7) Rim lighting on characters
8 ) A huge streaming world without load screens
It has nothing to do with console war bullshit, it's just straight up impressive to see such techniques implemented on such old hardware. Just ONE of those features in another PS2 game would be impressive, but to squeeze ALL of that in? It's no wonder the performance was lousy. The fact that a lot of Japanese developers of modern games can't even implement that stuff into their 360 and PS3 games makes this feat seem even more impressive.
As an aside, here's a video of the fifth colossus (that was posted above running on an emulator) as it was seen on a real PS2.
VIDEO 
