I might make a soul successor to this game myself if I stick with Unity and get through making my current idea. Can't imagine a game like this would be too hard to make, especially in an EZ Mode program like Unity
It's still an aspiration of mine to pull an EIREXE and properly have a look at the internals of this game, I have a basic knowledge of reverse engineering and am trying to read a bit more every day, but I think I'm still a way off.
I actually do (not very good) Brawl modding and Melee modding. I'll look into what I can do with Shrek. This thread is pretty old, but I can still check it out. Nothing I can do for Shrek 2, but I should be able to make the game better. I'm actually not too good at modding Wii and GC and just started learning. Depending on the filesystem I might be only able to do texture stuff, but that would also be cool I guess since most of the costumes aren't very good. I could try my best and see what I can do though, if I can't do much I'm just gonna revisit Shrek Superslam modding when I'm better. Hopefully someone can make something better than I can though.