All this is good for Nickelodeon, but is it good for the Gameboy Advance?
The answer is, well, sure.
Gameboy Advance fans are now bobbing right in the middle of the wake of the very popular Nintendo DS. All serious title development is going to the DS (and to other consoles), leaving family-friendly titles, mostly from successful licenses (like Drake & Josh) for the GBA. Those same GBA fans will have to enjoy this while it lasts; within another year or so, they probably won't even be getting Drake & Josh-style games ...
Considering that Drake & Josh is based on the TV show of the same name, the graphics are somewhat downsized from TV quality (that's a joke). They're not on par with anything else most folks are playing right now, either. PS3, Xbox 360, Wii ... forget about it. This is a game that's totally aimed directly at the amazingly huge exiting GBA installed base and the graphics quality (or lack of same) was never an issue when the decision was made to develop this game. So don't even bring up graphics quality, or audio, for that matter, as a factor in buying or not buying Drake & Josh for GBA. You're going to buy it because you enjoy the show and you think you might derive a few moments of fun from playing a game based on some of the content therein.