See, I think they're pretty precise. I usually end up making the game a lot harder for myself by finding retarded challenges like trying to fling a hammer bro into the lava with yoshi's tongue in midair (came close, but I accidentally stomped on him in the air before he could land in the lava
) or landing precise triple jumps in Bowser's stages while narrowly avoiding everything and randomly busting out sideflips or whatever. That's why I love these extra 120 stars; they require my kind of dicking around to find.
Actually, I do that a lot in Mario games. I just like seeing what kind of cool shit I can pull off, but I get a lot more into it with Galaxy 1 and 2. And Sunshine too, though I liked fucking around in that game more than the actual missions. At least Galaxy and Galaxy 2's missions are fun, and you really don't repeat much in the latter. One mission, you're spitting Bullet Bills at shit, the next, you're gliding a bird through a crumbling space station, then you're drilling through a house while the direction of gravity changes.
The only changes I would make to the sequel is to bring Splatter Matter back, get rid of the Fat Luma character, and have Bowser only appear once, with the Koopa Kids filling in all of the main boss fights leading up to him. They made the same stupid mistake of repeating the Bowser fight 3 times, and while they do add twists each time (the finale is actually really cool), it just loses it's impact. But everything else is really, really solid. Technically, a better game than the original in almost every way.