I wonder how Heavy Rain compares to Alan Wake. Those two seem to be the rivals of each other in terms of graphics. Alan Wake has been in development for quite some time too. I think they started in 2005 (not sure). Heavy Rain was actually multi-platform at first too by the way, but then got canceled for the X360 (don't remember why exactly).
I still believe KZ2 and GeOW2 are too different in art style to actually tell which one looks better. Engine wise, KZ2 can do some stuff that is not implemented in GeOW2, true, like the advanced blur, lighting and particle effects, but on the other side, the chaotic look (especially texture wise) on GeOW2 surpasses KZ2 by a long shot, and imo GeOW2 looks sharper (probably because of less blur to hide stuff) and the surroundings are simply more "crowded" instead of lots of grey square textureless walls and boxes. Even though KZ2 might give a much better experience with its art style (and especially alpha blending with smoke, dust etc), one should be able to recognize that KZ2 is not THAT far above GeOW2 in graphical power.
Maybe the PS3 is more powerful overall, especially since they can use the cell to calculate graphics, physics, audio and a lot more. But the PS3 has a very big problem, and that's the split memory..
Truth does not fear investigation
