An up and coming DC coder, Wauters Kris has released an image converter and a shuffle style puzzle game for the DC. His win32 based image toolkit allows you to convert BMP, JPG, or GIF images files into DBP (Dreamcast Binary Picture) file format for viewing with this source on the DC.
The shuffle game is a simple picture shuffle type game, give it a try

Note that this is not a CD image, and you will need a serial or BBA to play this. For info on turning this type of file into a booting CD-R (or a bootable CD) checkout the tutorials section in the DCDEV section.