If the GameCube version of Madden is a fancy new washing machine (looks great, impressive stats, more than you can handle) and the DS version is a budget washer-dryer (cheaper, looks okay, big strides forward in one key area), then the GBA version is a bloke coming round your house, standing over the bath and swilling your pants around with a wooden stick.
You'd have to award points for ambition - but otherwise it's an experience you'll be begging to forget.
Madden worked on DS because the stylus gave it an extra edge and every feature in the full fat versions made it in. GBA's lack of a stylus, relative power, and the removal of key Madden modes like Franchise make it a pointless buy unless you don't own a DS or - freakishly - any other games console.
You can still string together plays, build up a playbook, innovate a bit in terms of strategy, and pull players and info from a decent-sized roster, but it's all played out in small-o-vision. And we're not just talking about screen size here. Everything's downsized to the point of it no longer really feeling exciting - or, we have to say, worth the effort.
It's got the basics, and fans can have fun, but it's effectively pointless if you've got a DS, and definitely pointless if you've got a GameCube.