I'm surprised people don't see the obvious Mario 64 influences in Galaxy, particularly the first SMG. It's basically Mario 64 with a different level design.
Anytime you're running away from bullet bills, guiding chain chomps, butt stomping puzzle pieces into place, collecting five star pieces, hitting a switch here to make something happen there, you're doing Mario 64 type things. Anytime you run and jump around on a small planet that you can't fall off from just for fun, or slingshotting yourself around one for the same reason, you're mimicking some of the best parts of Mario 64. Is it pointless? Yes. Is it fun? Yes!
The new emphasis on bosses as part of the regular stages introduced in Mario 64 continued into Mario Galaxy and culminated in some truly awesome designs in SMG2. Even the suits in the Galaxy games work the same way they do in 64. In 3D Land, most suits help you survive a level. In 64 and Galaxy, they are the level. Particular stars require certain suits to advance, and the level design is built around their use.
Mario 64, even in it's regular stages, has much more platforming than Sunshine, and especially Banjo Kazooie. The rapid switches from exploring a level to passing designed obstacles and back to exploring is something that was introduced in Mario 64 and continued brilliantly in Galaxy. They just fine tuned it and tilted the balance towards more platforming, less exploration. I think Galaxy has more in common with 64 than Sunshine does.