Didnt Amiga Computing magazine do the source and step-by-step for Jolyon Ralph (what happened to him?) demos? There was "Zowee" with the bouncing Tuts (yes, thats Tuts), and another which was a 64 colour (EHB) affair but cant remember the name?
EDIT - Found him - he is the MD of a company called "Mysterious Ways". On there site, there is some good amiga
How To Code docs.