*Laughs at Segafan*!
Look at the videos of each game first. Mario Sunshine kicks WW in the bollocks.
But yes, it is a true game, being developed by Treasure, the same dev house that made Sin and Punishment and Mischief Makers.
The game will stay true to its roots, and from what I heard, is still mainly 2D, though that shouldn't take away the fun

. I'm looking foward to it, but no way in hell will this come close to Mario, not in scope, design, and I doubt fun either.
I loved the GB games, I hope that the game retains it's playability though, and maybe treasure can improve the gameplay.