I have it for the PS2, which I assume would be identical/almost identical to the GC version.
It's certainly one of the better anime fighting games out there but that's not saying much. It's developed by Eighting who develop just about every anime console fighting game around, so it plays similarly to their other games, if a bit more refined. D.O.N is basically Jump Superstars / Smash Bros, with a hint of Dream Mix TV and Narutimate Hero (in that when you smack your opponent you can collect their energy in order to pull off specials) and kinda reminds me of FullMetal Alchemist Dream Carnival (though Dream Carnival plays like turd).
Basically D.O.N is no where near as good as Jump Superstars or Super Smash Bros (obviously) and to be honest I certainly wouldn't put down $50 to import it, but it is a pretty fun game you could easily whittle away a few hours on. =)
Speaking of fighting games one title I am quite impressed with is the new Super Dragonball Z game, the last one I played was Bukodai 3 which I didn't particulary like, but Super DBZ is by a different developer and more like a traditional arcade fighter. Controls are straight forward, action flows well, uses Japanese voices and the cell shaded graphics are very, very impressive. I was quite suprised with it!
The best anime fighting game IMO is still Narutimate Hero 3 though, which kicks ass. Havn't played the Naruto GC fighting games mind you, but I hear they are very good.