It was really nice of Nintendo to give us Ambassadors all of these free GBA games, but man, they looked all stretched and washed out. I remember these games being beautiful. Is my memory fading, or is it the 3DS pulling some funny sh*t?
It's the 3DS, of course. Nothing's wrong with the top screen, but something is up with how legacy games are stretched to fit it.
Here's the easy fix: Hold SELECT when starting a 3DS game. That's it! The system will change the display mode to show the title in its original resolution. This also works with Game Boy games, and the system displays a cute Game Boy frame graphic around your title.
The only drawback is that the original resolution is much smaller. Still, I'd rather enjoy the game in its non-stretched form.