Digging up an old thread...
Well, by the time Ravenworks released the demo, the movement, music, and enemies were already programed. It really does seem like such a waste to have all that work completed and then just drop it to make a buck on WiiWare.
Seriously, this game practically fits the DS like a glove! They don't need to add in SO MANY extra features to rival the Wii; we hardcore Cave Story lovers will appreciate the game itself on the handheld.
And there's my two cents.