Super Mario Advance 2: Super Mario World is one of the first games released for the Game Boy Advance. It is pretty much a straight port of the original Super Mario World for the SNES.
The game looks extremely sharp on the GBA. I think it looks even better than the original, and there are some new sound effects thrown into the mix.
Although the gameplay is basically the same, it is a little bit more difficult to control, since there are only two face buttons. I've found using the shoulder buttons too often to be a bit awkward. I also think that the game is quite a bit easier than the original. In this port, when you are hit by an enemy while Fire or Cape Mario, you will revert to Super Mario instead of small Mario. Also, this version saves your lives in between playing sessions, making it easy to amass huge numbers of lives.
This is still the same great classic platformer, and if you don't mind the toned down difficulty, it's a good port.