Before ever playing this game, I knew it was the black sheep of the 3D Mario games. It doesn't feature classic Mario enemies, has an actual story, and has these weird knockoff power star imitations called the shine sprites. But.... Sitting down to 100% this game on the Game Cube was probably the most interesting and most fun experience I've ever had with a 3D Mario game.
As for the jank and difficulty, I actually like it. When something is difficult and takes days to complete, it tends to stick with me more. There are times that I wish the modern 3D Mario games were this difficult. Besides that, the thing I like most about this game is how creative the hidden shine sprites and blue coins are. Having to spraying down the only yellow bird in a level so that it produces a shine sprite? Genius.
For the entire game being beach themed, the level settings are quite creative. My favorite setting would probably be Noki Bay, with all its hidden passageways scaling its giant wall. My second favorite would be Hotel Delfino with "Mysterious Hotel Delfino" being my favorite mission in the game.
There's so much more I could say about this game. It's easily one of my favorite games of all time.