That is why I like it. I thought the Hub World of Galaxy was awful. Unlike Delfino Plaza and Princess Peach’s castle, it wasn’t fun to explore. It slowed down the pace of the game tremendously, and the levels themselves were overly simple and easy. Yes, Galaxy 2 basically is a truncated version of the first game’s story - but it puts the focus on what Mario games should focus on: The level design and gameplay. The levels were leagues better and often far more challenging than anything in the previous game. The new additions, like Yoshi’s, offered unique level gimmicks that fleshed out the style of galaxy to near perfection.
Disagree -- the hub wasn't a barrier in Galaxy 1 at all, since it was very quick to get across it.
But the hub's developing narrative was beautiful. The sense of a real adventure is unparalleled in the franchise, from the first quiet moments when you run around a small planetoid chasing the rabbit, to seeing bits of Rosalina's past unfold as the ship comes to life. Mario's head-ship in G2, on the other hand, was so stagnant it felt like a placeholder that they forgot to populate. It never changed or developed at all, it was just this weird extra thing before the level select.
The mix between journeying far into unknown space, seeing strange planets along the way, seeking to find the Princess but
also slowly revealing Rosalina's story about the loss of childhood... it's like a meta-game for everything Mario. It's absolutley lovely, and of course the brilliant Koizumi was responsible--sadly Miyamoto pushed him back for the sequel.
I also found the level design to be greatly superior in the first game. It balanced the 2 pillars of 3D Mario much better, which are (1) free exploration and (2) goal-seeking. Those have to be kept in harmony. For instance, most levels in Mairo 64 were like little toy sandboxes to run around in, even though it also had some pathways designed to feel more like normal levels. That's the 3D Mario concept, and it depends heavily upon open, freely explored areas that are like little surprise gardens. Galaxy 1 has tons of these.
In G2, it's as if they wanted to give up on 3D Mario's whole concept, regress the franchise to the point where they apparently forgot even the lessons of Mario 64, and focus on linear courses (or linear courses disguised as non-linear due to a couple of small open areas along the middle)... but that takes away the magic of journeying into new planets and exploring them.
Even the semi-linear levels in G1 are just better. Nothing in the second game tops the glass pill in the middle of one of the first levels of G1, with the gorgeous pacing as you approach it. I miss that sense of quiet wonder that the first game so often gave you, with its soundtrack and its frequent moments of pause without any "next objective" in your face.