Real Game Boy games are a challenge to code, not only you have to deal with restriction such as low CPU power, also the limited color scale (if you can talk about colors at these grey scales at all) is distracting new coders to get familiar with this system.

HuCABBAGE is one of the newer homebrew coders who picked up the challenge and the result is The Bouncing Ball, initially released for the GB Jam 4.

Guide your bouncing balls around obstacles or try to avoid them at all. There are really plenty of levels, which makes this game outstanding.

http://gb.lifeabroad.org/blog/the-bouncing-ball/