This is the best Mario old-school game ever. The enhanced graphics of Super Mario All Stars are used in this GBA version
The game play is somethng like Super Mario World, but the map screen has some differents things about it. Besides just selecting the next stage from the map, you can select mini games in which you may earn extra lives at no risk of losing the ones you have. You are, at times, forced into a battle against Hammer Bros, Boomerang Bros, and even Fire Bros. On the map, you may also select Mushroom Houses, in which you must choose 1 of 3 chests which will yeild an item. The wide variety of items in this game also make it very different than the other Mario platformers.
The items consist of:
Mushoom: turns you into a bigger Mario.
Fire Flower: lets you throw fire balls.
Super Leaf: turns you into raccoon Mario, thus enabling you to fly briefly once your running speed reaches it's maximum.
Tanooki Suit: turns you into a type of Raccoon Mario, only with more coverings so it actually a suit. The other ability is being able to briefly transform into a statue upon command. This is good because enemies cannot attack you as a statue.
Frog suit: lets you swin faster in the water by letting you use the d-pad to move under water.
Hammer Suit: gives you the Hammer Bros' armor and lets you throw hammers. These hammers are far more powerful than fire balls. Also, ducking will make incoming fire balls disappear upon hitting you.
There are more items which will help you on the map, but I will not go on about those.
The music is also very good and gives you the feel of a great Mario game.
If you like Mario games and have missed this one, you should get this as soon as you can.