The Pokemon Mini could be called a "dedicated Pokemon handheld console". Its specifications are low-end, but its novelty more than makes up for that. Writing a Pokemon Mini homebrew seemed unworthy at first, but then I became more interested and actually did it!
Mini Cookie is a tech demo where the player controls a hungry bear, eating the cookies scattered all over the screen.
Downloads
Mini Cookie ROM - download this to run it in an emulator (I recommend PokeMini)
Source code - Mini Cookie source code package
Dev kit with ready-to-compile source code for Mini Cookie - get this if you wish to compile the Mini Cookie ROM yourself, or if you'd like to develop your own games using this as a starting point! Tested in Windows XP.
Featured in Retro Gamer issue 140