Yes, some of Mario's moveset from other games has been removed, but did the game really require a more complex set of controls? 64 and Sunshine are very open-ended games with a big emphasis on player exploration and discovery. Those games needed an array of moves to facilitate swift, functional movement as the world was very big.

64 and Sunshine didn't actually need those complex controls though. Most people will have played them just fine without going much beyond run, jump, and maybe long jump.

The depth of the controls do appeal to a subset of players who become skilled with the extra moves and find joy in really experimenting with levels and finding unique or very fast ways to progress through them. That's the beauty of it - the game works fine for the more casual player but has something for more experienced gamers as well. It's the perfect example of 'easy to learn, hard to master' that make Nintendo's classics so universally loved and replayed throughout the decades.

He also starts talking about the realistic gravitational pull on a planet shaped like a question mark. What is the point of this analysis? Of course it's not going to be realistic. What did he expect from a game aimed at 7-11 year olds?

You really didn't understand what he was saying. He's saying the unrealism of the gravity is a positive. The point he's making is that realism is not important. The designers use gravity in a way that is only superficially like the real world and yet is immediately understandable.

Don't get me wrong. Galaxy isn't without its imperfections but I really feel that he is clutching at straws in attempt to make an "in-depth" review of something that is, in its nature, quite shallow.

It's not shallow at all! If game design was that simple we'd have games as good as Mario Galaxy coming out of our ears. The industry is littered with mediocre titles because their creators don't put as much thought into what they are making and how it would be experienced by the player.