I'm starting to remember why this game was my least favorite 2D Mario.
Don't get me wrong, it's still a fun and well-designed game. It has some variety, and it has 99% of platformers beat. The problem is that, compared to the NES Mario games, World just seems to lack imagination. The first Mario had an Italian plumber stopming his way through an army of evil turtles in order to free a land of mushroom-people. The second "Mario" game was a trippy journey through a dreamworld. Mario 3 had a ton of bizzare power-ups and themes. By contrast, World just feels like a by-the-numbers platformer.
The fact that it released relatively close to Mario 3 only heightens the disappointment. Mario 3 let you turn into a racoon who could fly or turn into a statute, a frog who swims in water and awkwardly hops on land, or a turtle who can throw hammers and duck into his shell for protection. You could even hop into a giant mechanical shoe and literally stomp your way through enemies.
Mario World replaces these with a cape and a ridable dinosaur, the latter of which almost never really adds anything (although I always take perverse pleasure in making him jump into lava. Seeing Yoshi slowly sink into a river of fiery death always makes me smile). I actually think the cape was a good power-up, as with enough skill it lets you fly through a whole level and dive-bomb enemies, but it still feels less imaginative than Mario 3.
The levels are also a big letdown compared to Mario 3. 3 led you through worlds where the enemies were four times your size, where you explored stages made of clouds, where the whole place was made of pipes and piranha plants, and where you found out that Bowser had a very threatening military, complete with a batallions of tanks, a massive air force, and a complete navy. Every world in Mario 3 had something new, creative, and different to offer, so progressing through the game always feels fresh.
World offers a series of places named after various foods, but which are mostly indistinguishable from one another. I can't recall seeing a single donut or other pastry in the Donut Plains, someone replaced the Soda Lake with water, and the Chocolate Island simply takes the prior levels and replaces all the colors with brown (which shows that Nintendo was once again years ahead of its time).
In this recent playthrough I've only just reached the Forest of Illusion, so I may be forgetting something from later in the game, but I can't recall there being all that much diversity or imagination in any of the levels outside of the Star Road. I can still remember several levels from each of the NES games, but despite replaying much of World just a few hours earlier, I'm hard pressed to remember anything special about any of them; World's levels don't leave any particular impression on me.
I know I'm coming off like I hate the game. I don't; I actually think it's a very well crafted and enjoyable platformer. But at the same time, I have to say that it feels more like a lost opportunity than any of the other Mario games. It feels like Nintendo had spent most of its ideas on Mario 3, and the small window between 3 and World left the latter with a lot less imagination. I'll keep playing to see if this impression holds up, but after almost twenty years I don't think my opinion is going to change much.