I beat it for the first time some weeks ago. Got like 110 stars. Did everything except for some 100 coin and blue coin stars, and the chuckster red coin mission. Game's good, but it's no more than good.
The physics are really iffy. There's a lot of weird quirks to Mario's movement, and a lot of jank around moving platforms like in this anon's second clip
>>1361382 that made the game endlessly frustrating to play. By contrast I played Vexx right before Sunshine and as mediocre as that game was I never had a problem landing pinpoint jumps with its controls.
Mario's air movement is weird. His X-axis and Z-axis acceleration work by different rules. Suppose you jump from a stand-still while facing forward; if you move the control stick left or right, Mario instantly gains a set amount of momentum in that direction, and when you let go of the stick, he instantly loses it. If instead you move the control stick forward or backward, Mario gradually accelerates in that direction, and when you let go of the stick he keeps all momentum gained. If you ever need to make an adjustment on both axes at once, for instance to land a precise jump on a moving platform, this system makes that needlessly unintuitive.
The hover nozzle is made tiresome to use by the game's insistence that Mario must slowly swivel around to face the direction he's trying to move to before being allowed to move in that direction.
The ground controls are much too sensitive. Acceleration is practically instant and even a tiny tilt of the control stick makes him move too fast, so in some situation you end up having to make a lot of quick microadjustments like in that above clip.
Also, it may just have been my controller, but it didn't feel like Mario had full 360 degree movement. If I make him run forward and slowly turn the stick left or right, it takes a while before I notice a change in his direction.
And that's just the most obvious stuff I can recall from memory. This isn't a huge deal if you're just running around an open level, and I did have good fun messing around with the moveset in those parts of the game, but it's a poor fit for the more precise platforming sequences the game loves to throw at you.
Outside of that, a lot of missions are a work of tedium.