As long as you don't cheat in multiplayer, there is nothing wrong with it

I hate it when you are playing with someone via internet/wireless and they cheat. I also hate when the leave the game because you are winning and they are not. 

I don't mind cheating if the player is playing by him/her self. Sometimes (in games such as Animal Crossing: Wild World (DS)) it is fun to use the HEX codes (Via Action Replay) to customize the game by finding the item codes (such as for a sign, tree, or building). I spent a few hours one time playing with the codes on my AR and learning what code gives what item. (a few days later, Codejunkies posted most of the codes I found, + about 5000 more - talk about disappointing)

I play Rhythm Heaven for DS 

I have played Rock Band and Guitar Hero, though.

Wow. It looks Excellent so far! I can't wait until the Pre-Beta is released! Every additional screenshot and video just gets me more excited for the game! You guys are doing a fantastic job.