Welcome, and enter the center Of my Super Mario adventure My girl is trapped on the other side of town So I'm movin' in leaps and bounds Folks around my way think I'm strange But there's a villain to blame Even my ma, she thinks I'm crazy But I've got to rescue Daisy (let's go!)
Instead of fireballs, the flower powerup gives Mario the ability to throw "superballs", weaponized balls which bounce off their targets at 90-degree angles. Nearly useless outdoors, but they can be fun when there's a ceiling. It did have the perk of collecting any coins it hit.
The game has two automatically scrolling areas. In the first, Mario pilots a submarine, the "Marine Pop"; in the second, he flies an airplane, the "Sky Pop". These are Unexpected Shmup Levels.
Koopa shells cannot be kicked, and are in fact bombs that explode after a few seconds of being stopped.
Instead of the usual eight worlds, the game has only four, with three levels to a world for a total of 12 levels, and no warp zones.
Antepiece: The game has great level design involving interesting yet accessible setpieces. One tool it'll use is to build up to a complicated setpiece with an "antepiece". In this image  you can see the third boss on the far right, who tries to crush Mario by throwing bouncing stones. On the far left, a positioned a little before you will encounter him, you can see one of those bouncing stones. That anticipatory stone presents no real danger, because it only bounces beneath the question boxes, which you can jump onto. The purpose of the stone is to warn you about what is ahead and maybe give you the opportunity to practice dodging and jumping on them in an enclosed environment.
Dolled-Up Installment: Like Super Mario Bros. 2, it was not originally a Mario game early in development. That is why it is about aliens invading Egypt, Bermuda, China, and Easter Island and why the only familiar face is Mario himself.
Four Element Ensemble: The variety of locations gives the game an exotic feel that most Mario games don't have. Each of the kingdoms, and the bosses associated with them, can also be associated with one of the classical elements. The Fire kingdm of Birabuto is based on the deserts of Egypt and ruled by the fire-breathing King Totomesu; the Water kingdom of Muda is a series of tropical islands and an underwater stage ruled by the seahorse Dragonzamasu; the Earth kingdom of Easton is a mountainous place filled with rocklike Ganchans and ruled by the Ganchan-throwing Hiyoihoi; and the Air kingdom of Chai is a series of highlands and a flying stage ruled by the mysterious Blokinton, who hides within a large cloud and attacks by hurling flying Chickens at Mario.
Giant Spider: World 3-2 and 3-3 will greet you to these guys.
Suspiciously Similar Substitute: Princess Daisy is so similar to Princess Peach/Toadstool that for over a decade, many people thought that she was Princess Toadstool, and that "Daisy" was just her nickname. In the Nintendo 64 era, she became a distinct Palette Swap for Princess Toadstool, and more recent games have given her a Southern accent and more of an Action Girl personality than her cousin.
The Palette Swap status is Older Than They Think — Daisy actually appeared with her more "modern" look in NES Open Tournament Golf.
Under the Sea: In World 2-3, Mario rides around in the Marine Pop and shoots down enemies and objects underwater.
Your Princess Is in Another Castle: This is Mario, and the game was hyped as the "true" sequel to Super Mario Bros. However, instead of rescuing a new citizen of Sarasaland after each boss, the false princesses were monsters in disguise.