You have to watch the HD version of the comparison clip to judge this and see that there is quite a big difference in grafix. I watched the SD version first and got the wrong impression that the difference is minor.
But the big let down is the small amount of zombies on the Wii version.
Don't blaim the developer though - why wouldn't he make his best to make use of the Wii hardware and make the best game possible?
I think this shows that processing power does matter, not only to make a beaitful looking game but sometimes is important for great gameplay also.







