Nicholas Scurfield’s review published on Letterboxd:
While Pretty much everything about Into the Spider-Verse was perfectly executed, and the animation was wholeheartedly deserving of the praise it was given, my rating maxes out at 3.5 stars due to the safe and standard plot. I really enjoyed each character, and even Kingpin was given a humanizing (yet simple) backstory for us to relate to. None of the other villains were given even the most basic considerations and were simply just "evil". One character that didn't really work for me was Dr. Octavius. In the beginning, She was made out to be some kind of slave or prisoner scientist working for Fisk, then as soon as she sees Spider-Man, she becomes purely evil for the rest of the film.
But the animation, as everyone would say, is beyond any other feature animated film in so many ways. I loved the ways the art style would change, sometimes for only a single frame, just to add emphasis or to play off of whatever was happening. It was incredibly creative, and I would re-watch Spider-Verse just to take it all in again.