Hero’s Quest is a proof of concept RPG for the Game Boy Advance. It features animated sprites, scrolling backgrounds, music, sound effects, menus, and other functionality. The game is implemented in C.
To play the game download the ROM and open it in with a Game Boy Advance emulator. VisualBoyAdvance (VBA) is a free emulator available for Linux, Mac and Windows. Instructions and controls are in the in-game menu.
You can browse the source on GitHub or download the rom.