The screen is something like 240x160. Anything 640x480 and less better not have a single dead pixel (Probably 800x600 by now). It's bad enough that they can't even port SNES or original Nintendo titles without chopping off the edges (Mario Advance series) or shrinking the level and character sprites (Donkey Kong Country, not technically a port). NES games played on the GBA require a "flicker trick" where certain lines of detail must switch every 1/60th of a second to show both lines of detail (Emulated; also not a port). At those illogically low resolutions, every pixel of detail counts moreso and you should not tolerate a single less pixel of detail. The resolution difference between the GBA and the older consoles seems to make people put more effort into ports and makes character sprites look bigger and more beautiful as well as makes some 3D games possible... So I can see some advantages in being lower resolution than an NES.
BTW, I own two GBASP units and two classic GBA units. Any negativity inferred above clearly does not phaze the the hold the GBA's greatness has on me!
PIC
Oh! And let me guess: You bought it for Metroid: Zero Mission, right? GREAT GAME but despite the trend of people saying it's the greatest game ever, Metroid Fusion make a lot more sense for people who never played the original Metroid... The music, title screen artwork/logo, character sprites, etc will seem unusualy bad to those who don't understand the way things were (It's 100% fan-service). ie, the box art shows a good example of the campy '80s power suit which just looks weird/dorky to those used to the Varia/Gravity suit and those playing Metroid for the first time.