I liked the game but had many complaints about it, especially after Mario 64.
My number one complaint is those damn blue coins. They were an absolute chore to get through, boring and completely pointless. The fact that some blue coins only appeared on specific Shines in a course was a joke, so not only did you have to search through the entire level, you had to search through the entire level through each individual shine. (what I mean is say in Shine 1 there is no circle in a spot, same in Shine 2,3,4,5,6, but then in 7 there is a circle hiding a blue coin). Similarly with the finding of 100 coins, only some of the episodes had enough coins that you could find.
The linearity of the game was annoying compared to Mario 64. In Mario 64 to face Bowser you have to get 70 stars, any 70 stars so every star you collected mattered even if you weren't going for 100% (except the 8 red coin one in the final bowser level). In Mario Sunshine, it didn't matter how many Shines you collected, all that mattered is that you collected the right shines. All those extra shines (including the blue coin ones) are completely pointless unless you are going for 100%. I loved the fact in Mario 64 that I went into a level and could collect almost every star, where in Sunshine you could only collect the one in that episode.
I did like FLUDD and mostly how Mario controlled (not Yoshi). The levels when FLUDD was removed were fantastic and some of the best around.