It's been a couple weeks now so if anyone wants to discuss spoilers, go right ahead. If you haven't seen the film yet, just beware of spoilers, though most of that will just be learning about references and Easter Eggs, since the plot isn't revolutionary or deep.
The film is a great kids film, lots of jokes for kids and adults to enjoy, funny slapstick humor, but the real charm, IMO, comes from all the references to the games across the Mario (and DK) series. There's just SO MUCH to pour over in every scene, both visually and auditorily. The score is just FILLED to the brim with references to all the games, both big and small, and any seasoned fan would be hard-pressed to keep up with them all. Of course, there are plenty of YouTube videos breaking down the score, so if you're curious about those, there's a lot to check out. I'd also suggest New Rockstar's breakdown of the film's Easter Eggs if you want to see what kind of hidden gems and nuggets the animators threw in.
I hope we don't get a direct sequel right away, if I'm being honest. I'd love to see a DK film and a Luigi's Mansion film. THEN make a Mario sequel, base it on Mario Sunshine, and have Luigi's absence make sense in that story by saying he's doing Mansion stuff. It'll feel like a cinematic universe without being too reliant on telling cohesive stories between films.
-Marc.