The best platformer games like Super Mario Galaxy are Super Mario Galaxy 2, Super Mario Odyssey and Astro Bot. Below are 9, each with the reason it is here — and, at the end, what filtering to platformer costs you.
Filtering to platformer means you want the movement itself to be the pleasure. It is the right filter when the thing you liked was getting from one place to another.
What you get: A game you can judge in ten seconds. Platformers live or die on the jump, and a good one feels right before anything else happens.
What made Super Mario Galaxy worth playing in the first place is covered on the full list. This page is the platformer part of that answer, and only the platformer part.
More of it, denser, and with Yoshi. Arguably the better game.
The successor, with a deeper moveset and less structure.
The only recent platformer with as many ideas per hour.
The same one-idea-per-level discipline, in four-player co-op.
The best indie take on this era of 3D platforming.
Every level a new concept, executed properly.
3D platforming built to be kind and full of small inventions.
The origin, and the moveset is still the deepest part.
Galaxy's diorama levels turned into a whole puzzle game.
Weight. Platformers rarely carry a story you will think about afterwards, and the collectible-led ones can become checklists if you let them.
The full list is on games like Super Mario Galaxy — 9 picks, no genre filter.
Super Mario Galaxy 2. More of it, denser, and with Yoshi. Arguably the better game.
No. Super Mario Galaxy released on the Nintendo Wii, but a recommendation is only useful if you can play it, so the picks above span platforms and eras. What they share is the genre and the reason.
Whether the move set is complete early. The great ones give you everything in the first level and spend the rest asking better questions of it; the weak ones drip-feed abilities to disguise thin level design.
Different games. 2D platformers are about precision on a single screen; 3D ones are about reading space and camera. Each pick below says which it is.
By hand. Each pick was written for the full Super Mario Galaxy list first, on what the game actually does, and this page is the part of that list that is platformer — never a genre tag lookup, which is how "best racing games like Super Mario 64" used to be a page on this site.
Or read the platformer guide for where to start in the genre generally.