News taken from GBAdev.org:

Frood is a scroller demo from Chris Berry:
Thought I’d send along this demo I threw together. It’s pretty ugly, and a bit “old skool” (I converted it from an Atari ST demo I wrote about 11 years ago 🙂
This demo used up most of the CPU time of the Atari ST, but on the GBA’s hardware it uses up hardly any at all.

http://www.gbadev.org/