After working on it for some time, I thought you may be interested to know I've now completed writing a visual/music GBA ROM.
It is called Splat! and after listening to some thoughtful comments from chipmusic.org users about using ROMs for their art, I've tried my best to make it a visually interactive musical experience rather than some cheesy attention-grabbing music player without compromising my initial idea of what the music should sound like. End users get to control (to an extent) the visuals and music for this ROM.
It is tricky to know how much control to give away for your own creation. I probably could have given away more control to the user but...I just wasn't comfortable doing that to be honest.
https://brokenspares.wordpress.com/2012
ten-splat/
Above is the link to my Wordpress page that has the ROM available to download.
(I know I should supply a direct link, but I've been awake for almost 19 hours, and I've just uploaded it to Wordpress, cut me some slack!)
Please do let me know what you think.
Also, ff anyone can point me towards any books to help with GB ROM creation, that would be appreciated too. (I basically want to know if I can use the 4 channels of the GB with the 2 Direct Sound channels simultaneously)
Right, and now bed...