I really like Game Boy development - one nice thing is that its graphics hardware is more regular in comparison to e.g. the NES, and its sound hw is legendary. Also fun is the DS, which although being far newer still retains the tile-and-sprite graphics hardware. Flash cartridges are also plentiful.
It seems to be the season of homebrew - Tobu Tobu Girl is another Game Boy game on a physical cartridge to come out this month, with full source code (also using GBDK) http://tangramgames.dk/tobutobugirl/
It seems to be the season of homebrew - Tobu Tobu Girl is another Game Boy game on a physical cartridge to come out this month, with full source code (also using GBDK) http://tangramgames.dk/tobutobugirl/