duh, of course it does. HAM is a software development kit for the Gameboy Advance system. go check it for yerself using the following link---
http://www.ngine.de/
and also check out
www.zonegn.com as therez a free homemade gba game there called "URANUS," a neat game that plays like 1942. the author of this vertical flight shooter is currently working on a GBA RPG project, if i am not mistaken...
<img src="http://www.pocket-dev.net/zonegn/uranus.jpg" A/>