Well, I initially loaded the builder image, but it was unable to format the disk. I was then directed to the manual partitioning-and-formatting notes by Roger - to do this I assumed I need to get a shell on the player. So, I loaded the developer image back onto the player's flash. This image boots, but it is unable to play anything, presumably because it can't find any files to play.
The player image seems fine, as does the visuals application - the only problem is that I don't seem to be able to get the player to quit to let me use the shell.