This game's main achievement is that it absolutely nails the expectations of a Psychonauts sequel. Rather than getting caught up in making up for lost time, or trying to reinvent what the first game did, Psychonauts 2 simply delivers exactly what the original backers paid for and fans of the first game wanted: More, modernised Psychonauts.
That's both for better, and worse- I think you can argue that the 3D collectathon platformer is best served by dense, open levels rather than Psychonauts' linear story based approach, combat and puzzles are definitely just "good enough" rather than exceptionally fun, and while Raz is still fun to control, Mario Odyssey has raised the bar a lot higher than he can reach anymore.
But, the story, character writing and symbolism is still there, and is still the draw that sets Psychonauts apart. Tim Schafer has undeniably still got it, even this game's least likeable characters are entirely a matter of poor placement within the plot causing their lack of development- You can still feel a more developed character underneath through that dialogue. It's really impressive that Psychonauts can make a whole cast of literal caricatures this endearing.
It's also still very funny. There are tons of gags good enough that you'll immediately want to share them with people. You need to bear in mind that this game's target audience is still the same kids who played the first, and it doesn't care if they've grown up or if they're new players- There's a few adult jokes that go over Raz's head, but he still has a ten year old's view of the world and the writing is very conscious to make sure a young kid can understand what's going on.
The most impressive thing about this is still that Double Fine picked up this franchise again after ~17 years, and it somehow feels like a day hasn't gone by. Psychonauts 2 somehow made everything familiar without feeling like a pointless rehash, and that on its own is worth experiencing.