So the feedback comes in the form of a sound when you miss. In Guitar Hero and Rock Band they’d skip a note when you missed, but you can’t really do that on Game Boy so I instead make a sound which has the same effect of screwing up the music.
Of course if you get a hit, I don’t want any sounds ruining the music. But yes, I can create a visual cue and am planning on making a sequel that will improve on this as well as add a number of other features and improvements.
I only started using GB Studio two weeks ago, but I’m learning a lot, and already have come up with a handful of new ways of doing things.