FLUDD was boring as it was overused,one powerup just didn't sit well with me.
The levels had no variety
Why did yoshi melt in water
Why was Bowser talking and the final battle in a damn toxic waste bath oh and why was Bowser 20x larger than usual
Camera was horrid
level design seemed less inspired than other mario games
It was over hyped to be a true evolution over SM64 but came up short
Some parts were just clumsy,this was not a difficulty thing as much as it was just a sloppy way of using the fludd when you had to control boats in some levels.
The diffilculty/Learning curve often flip flopped keeping the game off balance
When Galaxy came out it was the game we were promised that sunshine was supposed to be,sunshine was not a bad game but did fall very short of expectations. Still a decent game but not great.