Wonderful movie on all levels, pun intended! Don't even listen to the 7/10 on IMDB, rigged by downvote spammers, nor the critics! It was simply excellent!
As with the first Sonic movie, Sonic is portrayed as a kid, living with a human family, still trying to find himself, and trying to be a hero. While this may be different than the Sonic we know in the games, who's a teenager that takes care of himself and already is a hero, this still works surprisingly well. The concept of him having to leave his home planet and be taken in by a human family may sound weird, but it works well. It's obvious how much they care for him and vice versa and want only what's best for him in spite of him wanting to become a hero.
I also loved the introduction of Tails. While Tails mainly came to warn Sonic about the danger of Knuckles wanting the Master Emerald, you could tell his and Sonic's bond was growing throughout the adventure, even if Tails was initially reluctant to come with Sonic for the adventure. We all know they're best friends in the games, but the way it was built up felt great. Working together, trusting one another, sharing their backstories on their home planet after the dance contest, including Tails' story of being bullied for being different, with Sonic calling him "pal", and their friendship continuing to grow even after that.
I also loved the lore with the seven emeralds growing to form the Master Emerald and how true it was to the games, including with Eggman wanting to steal it, Knuckles' tough guy attitude of reluctantly working with someone as long as he gets what he wants in exchange, etc. Tails being good with gadgets and inventions was also true to his character in the games. The trio also finally forming a team to take down Eggman and the fight against him also felt true to the games. Not to mention, it was also emotional when Sonic and Knuckles finally got to exchange backstories shortly before the team-up, and how both their backstories were tragic in similar ways, but how Sonic finding a caring family helped him, and he told Knuckles that there was hope for him too in the same regard.
If there's any tiny nitpicks I might have, it's that I would have liked to know a bit more about the mother owl, and Sonic's life on his original home planet. Perhaps a bias, but I also would have liked to have seen Tails bond more with the humans, just as Sonic did in the first movie and this one. I semi-agree that the Hawaii plot wasn't entirely necessary, but I didn't feel like it was a complete waste of time, nor do I feel like it took up as much time as some people claimed. Each time they transitioned to it, it was maybe a couple or a few minutes long at most, and then right back to the adventure aspect of it with Sonic and crew.
Just like the "AUDIENCE SAYS" on Rotten Tomatoes, this is like a video game come to life! Filled with adventure and great character interactions! The people rating this 1 star saying it's a waste and nothing like the games are just biasedly mad that this dares to be slightly different than the games in some ways (such as Sonic's story and him being a kid rather than a teenager). But don't let that convince you that it's not mostly true to the games or awesome in terms of overall, because it absolutely is! Will definitely be watching this a second time!