Keen on a Rockford remake for GBA? Zapf Bandit coded one and you can download it from gbadev. Here is what the coder said:

Here is my first real GBA game. It is a very accurate recreation of one of my favorite every DOS games.It is not 100% complete but unfortunately I can’t make it to a few of the levels in the original so I’m not sure what some of the blocks are… If you are a rockford fan please let me know what they are when you get to them.

http://www.gbadev.org/